Non-silicon device heterolayers on patterned silicon substrate for cmos by combination of selective and conformal epitaxy

ABSTRACT

A single fin or a pair of co-integrated n- and p-type single crystal electronic device fins are epitaxially grown from a substrate surface at a bottom of one or a pair of trenches formed between shallow trench isolation (STI) regions. The fin or fins are patterned and the STI regions are etched to form a height of the fin or fins extending above etched top surfaces of the STI regions. The fin heights may be at least 1.5 times their width. The exposed sidewall surfaces and a top surface of each fin is epitaxially clad with one or more conformal epitaxial materials to form device layers on the fin. Prior to growing the fins, a blanket buffer epitaxial material may be grown from the substrate surface; and the fins grown in STI trenches formed above the blanket layer. Such formation of fins reduces defects from material interface lattice mismatches.

BACKGROUND

1. Field

Circuit devices and the manufacture and structure of fin based circuitdevices.

2. Description of Related Art

Increased performance in and yield of circuit devices on a substrate(e.g., integrated circuit (IC) transistors, resistors, capacitors, etc.on a semiconductor (e.g., silicon) substrate) is typically a majorfactor considered during design, manufacture, and operation of thosedevices. For example, during design and manufacture or forming of metaloxide semiconductor (MOS) transistor devices, such as those used in acomplementary metal oxide semiconductor (CMOS), it is often desired toincrease movement of electrons in N-type MOS device (n-MOS) channels andto increase movement of positive charged holes in P-type MOS device(p-MOS) channels. However, performance and movement are slowed bylattice mismatches and defects generated in a between layers ofmaterials used to form the MOS.

For some CMOS implementation, the co-integration of lattice mismatchedmaterials like III-V and IV material epitaxial growth on Silicon is abig challenge. Currently there is no state of art solution toco-integrate n- and p-MOS material epitaxial growths on to a singleSilicon substrate. In addition, in current applications, due to largelattice mismatch in materials, crystalline defects are generated whennovel materials (e.g., type III-V and IV (e.g., Germanium)) are grown ona Silicon material substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross section view of a portion of a semiconductorsubstrate base after forming a layer of shallow trench isolation (STI)material on a top surface of the substrate.

FIG. 2 shows the semiconductor substrate of FIG. 1 after forming STIregions and a trench between the STI regions.

FIG. 3 shows the semiconductor substrate of FIG. 1 after formingepitaxial material in the trench between the STI regions.

FIG. 4 shows the semiconductor substrate of FIG. 1 after patterningepitaxial material formed in the trench, and after etching the STIregions to form an electronic device On from a height of the fin layerextending above etched top surfaces of the STI regions.

FIG. 5 shows the semiconductor substrate of FIG. 1 after forming a firstconformal thickness of a first conformal epitaxial “cladding” materialgrown from sidewall surfaces and a top surface of the electronic devicefin.

FIG. 6A shows the semiconductor substrate of FIG. 1 after forming asecond and a third conformal thickness of a second and a third conformalepitaxial “cladding” material grown from sidewall surfaces and a topsurface of the first conformal thickness.

FIG. 6B is a schematic top perspective cross section view of examples ofFIG. 6A, with a device gate buffer material formed over a portion of atotal length of the channel material;

agate dielectric material or a gate electrode material formed over thedevice gate buffer material; and a junction region material (of twojunction regions) formed over two portions of a total length of thechannel material.

FIG. 6C is a schematic top perspective cross section view of examples ofFIG. 6A, with a device channel material; agate dielectric material or agate electrode material formed over a portion of a total length of thedevice channel material; and a junction region material (of two junctionregions) formed over two other portions of a total length of the channelmaterial.

FIG. 7 shows the semiconductor substrate of FIG. 1 after forming STIregions and two trenches between the STI regions.

FIG. 8 shows the semiconductor substrate of FIG. 1 after forming a maskover material in a second trench, and forming second epitaxial materialin the first trench.

FIG. 9 shows the semiconductor substrate of FIG. 1 after polishing andpatterning epitaxial material formed in the first trench, removing themask from over the second, forming a mask over the first trench. andforming a second and third epitaxial material in the second trench.

FIG. 10 shows the semiconductor substrate of FIG. 1 after polishingepitaxial material in the second trench and removing the mask over thefirst trench to form epitaxial region in the second trench.

FIG. 11 shows the semiconductor substrate of FIG. 1 after patterningepitaxial material formed in the trenches, and after etching the STIregions to form electronic device fins from a height of the fin layersextending above etched top surfaces of the STI regions.

FIG. 12 shows the semiconductor substrate of FIG. 1 after formingconformal thicknesses of conformal epitaxial “cladding” materials grownfrom sidewall surfaces and a top surface of the electronic device fins.

FIG. 13 is a schematic cross section view of a portion of asemiconductor substrate base after forming a layer of epitaxial materialon a top surface of the substrate, and a layer of STI material on atopsurface of the epitaxial material.

FIG. 14 shows the semiconductor substrate of FIG. 13 after formingtrenches between the STI regions.

FIG. 15 shows the semiconductor substrate of FIG. 13 after forming amask over material in the second trench, and forming second epitaxialmaterial in the first trench.

FIG. 16 shows the semiconductor substrate of FIG. 13 after polishing andpatterning epitaxial material formed in the first trench, removing themask from over the second, forming a mask over the first trench, andforming a second and third epitaxial material in the second trench.

FIG. 17 shows the semiconductor substrate of FIG. 13 after polishingepitaxial material in the second trench and removing the mask over thefirst trench to form epitaxial region in the second trench.

FIG. 18 shows the semiconductor substrate of FIG. 13 after patterningepitaxial material formed in the trenches, and after etching the STIregions to form electronic device fins from a height of the fin layersextending above etched top surfaces of the STI regions.

FIG. 19 shows the semiconductor substrate of FIG. 13 after formingconformal thicknesses of conformal epitaxial “cladding” materials grownfrom sidewall surfaces and a top surface of the electronic device fins.

FIG. 20 is an example process for epitaxially cladding a first conformalthickness of a first conformal epitaxial material on sidewall surfacesand a top surface of a single crystal electronic device fin after thefin is epitaxially grown in a trench formed between STI regions, andpatterned to form a height of the fin layer.

FIG. 21 illustrates a computing device in accordance with oneimplementation.

DETAILED DESCRIPTION

Large lattice mismatch in materials may generate defects when certainmaterials (e.g., type III-V and IV (e.g., Germanium (Ge)) atomic elementmaterials) are epitaxially grown on a Silicon material substrate (e.g.,single crystal silicon). In some cases, the materials may be epitaxiallygrown from a substrate surface, in trenches between shallow trenchisolation (STI) regions. The growth may be patterned and etched to form“fins” of material in or on which devices may be formed. Thus, thedefects may exist in “fins” of material in or on which devices may beformed, after the fins are patterned and etched from the growths. Ifthese defects propagate throughout the trench, they can lead to yieldand variations issues in a device built on a device layer formed fromepitaxial growth extending above the trench. This propagation may existin “fin” devices formed in fins that are patterned and etched fromepitaxial growth extending above the trench. Such fin devices mayinclude fin integrated circuit (IC) transistors, resistors, capacitors,etc. formed in or on sidewalls of “fins” grown from or extending above asemiconductor (e.g., silicon) substrate or other material. Such devicesmay include fin metal oxide semiconductor (MOS) transistor devices, suchas those used in a complementary metal oxide semiconductor (CMOS) basedon movement of electrons in N-type (e.g., doped to have electron chargecarriers) MOS device (n-MOS) channels and movement of positive chargedholes in P-type (e.g., doped to have hole charge carriers) MOS device(p-MOS) channels.

Embodiments describe herein provide a solution to processes that trapdefects only in one direction of the fin (along width W, such as shownin FIG. 2-6). The solution may include a process that uses the conceptof aspect ratio trapping where Height (H) of the fin is larger than thewidth (W). However this scheme leaves large number of defectspropagating towards the device layers in the long direction of the fin.According to embodiments, such defects can be avoided by trappingdefects along the sidewall of the STI forming the trenches (e.g., inboth the W an length L directions) by making the Height (H) of thetrench larger than the width (W) and length (L) of the trench such thatratios H/W>=1.5 and D/L>=1.5. This ratio (e.g., aspect ratio trapping or“ART”) may give a minimum H/W ratio limit to block many defects within abuffer layer formed within the trench. Thus, the processes describedherein may avoid crystaline defects in the fins due to lattice mismatchin the layer interfaces. For example, defects (e.g., crystaline defects)in the trench may not have extended into or not exist in the epitaxyregions (e.g., the upper device material of the regions). Thus, the finsformed from that material may provide electronic device material (e.g.wells and/or channels) in which defect free fin based devices may beformed.

According to some embodiments, Fin FET well and channel materials orlayers may be grown using: (1) blanket buffer layer growth, (2) growthin a trench, and (3) growth of a cladding layer around a Si fin. Whileeach of these is considered, it is noted that approach (1) may not allowp- and n- co-integration and may require thick buffer layers to be grownto reduce defects in device layers. Also, approach (2) may allow CMOSintegration, however may require very deep narrow trench to accommodateall the buffer and device layers to be grown within the trench (e.g.,see ART noted above). Next, approach (3) may not allow thick normulti-layer cladding layer to be grown around Si fin if there is a largelattice mismatch between Si fin and cladding layer.

Consequently, some embodiments described herein include growth of bufferlayers in a trench followed by growth of device layers as “cladding”.The approach helps to alleviate issues present in other fin FETs and finFET formation processes (e.g., such as those noted above). Some proposedembodiments integrate non-Si device heterolayers on patterned Si forCMOS by a combination of selective and conformal (e.g., “cladding”)epitaxy. Multi-buffer layers are grown in a trench such that the toplayer in the trench has a lattice constant equivalent to the channellayer. This top ART layer could either be the channel layer or the highbandgap buffer just below the channel layer. Next STI may be recesseddown to form a fin in the top layer. One or multicladding layers canthen be grown around the fin to either generate agate layer on whichhigh-k dielectric/metal gate is later deposited or to form a combinedchannel and gate layer cladding. In another embodiment, highly dopedepitaxial material can be grown on top of the gate cladding layer toreduce the resistance of the source/drain region.

In addition, embodiments describe herein provide a more efficient andreliable process for forming both p- and n-type epitaxial electronicdevice fins from the same substrate by integrating very large scaleintegration (VLSI) compatible fin structures with selective epitaxialgrowth and fabricating devices thereon. Such integration may includeepitaxially growing a fin layer of a fin epitaxial material from asubstrate surface at a bottom of a trench formed between a plurality ofshallow trench isolation (STI) regions having STI sidewalls defining afirst width and a first height of the trench. The trench height may beat least 1.5 times its width. Then, a top surface of the fin layer maybe patterned and the STI regions may be etched to form an electronicdevice fin from a height of the fin layer extending above etched topsurfaces of the plurality of STI regions (e.g., an “exposed” device wellor gate layer). Then, a first conformal thickness of a first conformalepitaxial “cladding” material grown from sidewall surfaces and a topsurface of the electronic device fin. Additional conformal thicknessesof a conformal epitaxial “cladding” materials can be grown from sidewallsurfaces and a top surface of the first cladding material and/or of theelectronic device fin.

In some cases, the epitaxial growth in the trench or of exposed fin maybe or include buffer layers in a trench and be followed by growth ofdevice layers, such as growth of cladding layers around surfaces of thefin to from a “tri-gate” device. Transistor devices can then be formedon the sidewalls and top surface of the fin.

In some cases, two fins are formed in adjacent trenches and clad withsuch cladding material. In some cases, prior to growing the fin layer, ablanket buffer epitaxial material may be grown from the substratesurface; and fin layers grown in STI trenches formed above the blanketlayer. Such formation of fins reduces defects from material interfacelattice mismatches.

Embodiments described herein allow p- and n- co-integration for CMOS. Inaddition, the elimination (or reduction) of lattice mismatch between thefin and the cladding layer allows growth of multi- cladding layerswithout creation of defects. Thirdly, the embodiments reduce thestringent requirements to make deep trench to capture all dislocationswithin buffer layers before the device layers are grown in the trench.

Thus, the embodiments describe herein provide for (1) co-integration ofn- and p-mos (e.g., forming of epitaxial trench material or regions forboth n- and p-mos) on to the same silicon surface for CMOSimplementation (e.g., and within certain length L, width W, and height Hrequirements as noted herein): (2) large reduction of defectspropagating to the device layers on both n- and p- side electronicdevice fins: (3) capture defects both along length L) and perpendicular(e.g., width W) to the electronic device fin vertical or height)direction, thus minimizing density of defects reaching active devicelayers or device fins (e.g., provides bi-directional aspect ratio (e.g.,selective “cadding”) trapping of crystaline defects, such as by allowingsingle or multiple device or gate layers to be grown from the sidewalland top surfaces of the fin material. In some cases, thehetero-integrated solution proposed can be utilized to make any devicearchitecture such as trigate, nanowires, nanoribbons, and the like.

FIG. 1 is a schematic cross section view of a portion of a semiconductorsubstrate base after forming a layer of STI material on a top surface ofthe substrate. FIG. 1 shows semiconductor substrate or base 101 ofmaterial 102 having top surface 103. Substrate 101 may include, beformed from, deposited with, or grown from silicon, polycrystallinesilicon, single crystal silicon, or various other suitable technologiesfor forming a silicon base or substrate, such as a silicon wafer. Forexample, according to embodiments, substrate 101 may be formed bygrowing a single crystal silicon substrate base material having athickness of between 100 Angstroms and 1000 Angstroms of pure silicon.Alternately, substrate 101 may be formed by sufficient chemical vapordeposition (CVD) of various appropriate silicon or silicon alloymaterials 102 to form a layer of material having a thickness between oneand three micrometers in thickness, such as by CVD to form a thicknessof two micrometers in thickness. It is also considered that substrate101 may be a relaxed, non-relaxed, graded, and/or non-graded siliconalloy material 102. Material 102 may be a relaxed material (e.g., have anon-strained lattice) at surface 103. Material 102 may be a singlecrystal silicon material. Substrate 102 may be made of silicon and havetop surface 103 with a (100) crystal oriented material (e.g., accordingto Miller Index). Substrate 101 may be a “miscut” substrate.

FIG. 1 also shows a layer of shallow trench isolation (STI) material 104formed or grown on top surface 103 of the substrate 101. STI material104 may be formed of an oxide or a nitride or combination thereof. STImaterial 104 may be formed of SiC or another material as know in theart. STI material 104 may be formed by atomic layer deposition (ALD) orchemical vapor deposition (CVD). STI material 104 is generally depositedvia Plasma Enhanced Chemical Deposition (PECVD). In some cases, any ofvarious oxygen precursors, Silane precursors, or generic precursors canbe used during a process (e.g., PECVD) to form STI material 104, as knowin the art. In some cases, STI material 104 may be formed by a processusing TEOS+O2+RF at 400° C.

In some cases, the bottom surface of material 104 may have the same(100) crystal orientation as that of material 102 (e.g., at surface103). In some cases. the bottom surface of material 104 may have thesame crystal lattice size as that of material 102 (e.g., at surface103). Material 104 may be a relaxed material (e.g., have anon-strainedlattice) with respect to its interface (e.g., where it is chemically oratomically bonded to the surface below) with surface 103.

FIG. 2 shows the semiconductor substrate of FIG. 1 after forming STIregions and a trench between the STI regions. FIG. 2 shows trench 105defined between STI regions 107 and 108 and surface 103. Regions 107 and108 may be formed by patterning and etching as known in the art. Thismay include forming a blanket layer of STI material 104, then patterningand etching material 104 to form STI regions 107 and 108. In some cases,patterning and etching material 104 to form the STI regions includesusing a resist or hard mask underneath a resist for the patterningmaterials. In some cases 1, 2, or 3 resist layers may be used for thepatterning materials. In some cases, patterning and etching material 104to form the STI regions includes using an O2 or O2/Ar plasma etch atpressures in the 10-100 mTorr range, and at room temperature. Suchpatterning and etching may also include etching an oxides including STImaterial, by etching with fluorocarbons (e.g., CF4 and/or C4F8), O2 andAr, at pressures in the 10-100 mTorr range. and at room temperature.

STI region 107 has sidewall 113 and top surface 117. STI region 108 hassidewall 115 and top surface 116. Sidewalls 113 and 115 may be verticalplanar surfaces perpendicular to (e.g., at aright angle with respect to)horizontal planar surfaces surface 103 and horizontal planar surfaces117 and 116. The sidewalls may comprise or be STI material 104. The STIregions 107 and 108 may have a width of at between 100 and 1000nano-meters (nm).

Trench 105 may be defined by the sidewalls of regions 107 and 108. Morespecifically FIG. 2 shows trench 105 defined by or having a side atsidewall 113 of region 107, a side at sidewall 115 of region 108, abottom at top surface 103, and a top adjacent (e.g., proximate) to topsurfaces 117 or 116. Trench 105 may include surface 103 of material 102exposed at the bottom of the trench, such as a planar or planarizedsurface of crystal material. In some cases, each of trench 105 isdefined by additional sidewalls of other STI regions, such as a frontand back STI having sidewall similar to sidewalls 113 and 115, and topsurfaces similar to surfaces 117 or 116, but defining length L of trench105.

Trench 105 may have width W1 defined by the horizontal distance betweensidewall 113 of region 107 and side at sidewall 115 of region 108. WidthW1 may be a width of between 10 and 100 nanometers (nm). In some casesW1 is approximately 25 nm.

Trench 105 may have height H1 defined by the vertical distance betweentop surface 103 and top surface 117 or 116. Height H1 may be a height ofbetween 30 and 300 nanometers (nm). In some cases H1 is approximately 75nm. H1 of the trench may be larger than the W1 of the trench such thatratio H1/W1 is >=1.5. In some cases, the ratio H1/W1 is =1.5. In somecases, the ratio H1/W1 is >=2.0.

Trench 105 may have a length L1 defined as the length going into thepage and along sidewall 113 or sidewall 115. Length L1 may be a lengthof between 10 and 100 nanometers (nm). In some cases L1 is approximately25 nm. In some cases L1 is equal to (or approximately the same as) W1.H1 of the trench may be larger than the L1 of the trench such that ratioH1/L1 is >=1.5. In some cases, the ratio H1/L1 is =1.5. In some cases,the ratio H1/L1 is >=2.0. According to some embodiments, W1 may bebetween 10 and 15 nanometers (nm) and H1 may be 350 nanometers (nm).Optionally L1 may be equal to W1.

FIG. 2 shows trench 105 defined between STI regions 107 and 108 andsurface 103. However it is contemplated that more, similar trenches andregions may exist on substrate 101 (e.g., such as at least hundreds orhundreds of thousands).

FIG. 3 shows the semiconductor substrate of FIG. 1 after formingepitaxial material in the trench between the STI regions. FIG. 3 showsfirst layer of material 122 epitaxially grown from surface 103 in trench105. Material 122 may be epitaxially grown from the crystal surface 103of substrate surface 103. Material 122 may be formed by epitaxial growth(e.g., heteroepitaxy growth) using atomic layer epitaxy (ALE), chemicalvapor deposition (CVD), Metal-Organic Chemical Vapour Deposition (MOCVD)or Metal-Organic vapour phase epitaxy (MOVPE), and may only grow from“seed” top surface 103 in the trench, but not grow from the STIsidewalls or STI top surfaces. In some cases, material 122 may be formedby epitaxial growth (e.g., heteroepitaxy) using molecular beam epitaxy(MBE), or migration enhanced epitaxy (MEE). Choice of growth depositionlike growth temperature, pressure of gas flux, etc may define theselectivity of the epitaxial growth. In some cases, the growth ofmaterial 122 is grown selectively from surface 103 by choosing or usinga predetermined growth temperature range, pressure of gas flux range,etc., as known for material 122 to grow from material of surface 103,but not grow from or initiate on material of the STI sidewall or topsurfaces.

Material 122 may be a first layer of crystalline material that hasheight H2 from surface 103 which is less than H1. Material 122 may havea bottom surface having a (100) crystal oriented material grown fromsurface 103, and side surfaces having a (110) crystal oriented materialalong or adjacent to sidewalls 113 and 115. In some embodiments,crystaline defects may exist in material 122 near or along the sidewalls113 and 115 of the STI forming the trenches. In some embodiments,crystaline defects may exist in material 122 due to defects, includingthe Stacking faults that originate at the STI sidewalls 113 or 115, thatstill remain within the trench 105.

Material 122 may have a top surface having a (100) crystal orientation(Miller Index). The top surface of material 122 may be polished oretched to form a flat surface having a (100) crystal index. Material 122may have width W2 between sidewalls 113 and 115. W2 may be less than orequal to W1. In some cases, the difference in width may be due tocrystaline defects in material 122. Material 122 may have a length L1.

Material 122 may have height H2 defined by the vertical distance betweentop surface 103 and a top surface of material 122. Height H2 may be aheight of between 50-150 nanometers (nm). In some cases H2 isapproximately 70 nm.

The bottom surface of material 122 may have the same (100) crystalorientation as that of material 102 (e.g., at surface 103). In somecases, the bottom surface of material 122 may have the same crystallattice size as that of material 102 (e.g., at surface 103). Material122 may be a relaxed material (e.g., have a non-strained lattice) withrespect to its interface with surface 103. In some cases, material 122is a relaxed layer (partially or fully) with respect to the substrate(e.g., surface 103).

FIG. 3 shows a second layer of material 132 epitaxially grown from a topsurface of material 122. Material 132 may be epitaxially grown from thecrystal top surface of material 122 by epitaxial growth (e.g.,heteroepitaxy growth) and may only grow from “seed” top surface ofmaterial 122 below the trench top, but not grow from the sidewalls orSTI top surfaces, similar to the description for growing material 122from surface 103.

Material 132 may be a second layer of crystalline material that hasheight H3 defined by the vertical distance between top surface 103 and atop surface of material 132. Height H3 may be less than H1. Material 132may have a bottom surface having a (100) crystal oriented material grownfrom material 122, and side surfaces having a (110) crystal orientedmaterial along or adjacent to sidewalls 113 and 115. In someembodiments, crystaline defects may exist in material 132 near or alongthe sidewalls of the STI forming the trenches. Material 132 may have atop surface having a (100) crystal orientation (Miller Index). The topsurface of material 132 may be polished or etched to form a flat surfacehaving a (100) crystal index.

Material 132 may have width W1 between sidewalls 113 and 115 in trench105. Material 132 may have a length L1.

Height H3 may be a height of between 10-400 nanometers (nm). In somecases H3 is approximately 200 or 300 nm. According to some embodiments,the difference in height between the top of material 122 and the top ofmaterial 132 may be 200 nanometers (nm).

The bottom surface of material 132 may have the same (100) crystalorientation as that of material 122 (e.g., at its top surface). In somecases, the bottom surface of material 132 may have the same crystallattice size as that of material 122 (e.g., at its top surface).Material 132 may be a relaxed material (e.g., have a non-strainedlattice) with respect to its interface with material 122 (e.g., at itstop surface). In some cases, material 3 is a relaxed layer (mostly orfully) with respect to material 122 (e.g., a top surface of material122).

FIG. 3 shows a third layer of material 142 epitaxially grown from a topsurface of material 132. Material 142 may be grown to height H1 abovesurface 103. In some cases material 142 have height H1-H3.

In some cases, material 142 may be a “device” layer, such as a layer onor which circuity devices are formed, as known in the art. Thus, thefins formed from material 142 may provide electronic device material(e.g., wells and/or channels) in which defect free fin based devices maybe formed. Such devices may include devices described herein. In somecases, material 142 may be a “buffer” layer, such as a layer on or overwhich a “device” layer will be formed, as known in the art. Material 142may be used to form an electronic device fin from an exposed height ofmaterial 142 (e.g., an “exposed” device well or gate layer) of the finlayer extending above an etched top surfaces of STI regions 107 and 108(e.g., see FIG. 4).

In some embodiments, material 122 or 132 are optional and not formed inthe trench, such as where material 142 is formed on layer 132 withoutlayer 122, or material 142 is formed on layer 122 without layer 132. Insome embodiments, only material 122, 132 or 142 is formed. In someembodiments, materials 122, 132 and/or 142 in the trench, as describedabove, are referred to as a single region, layer or material.

Material 142 may be epitaxially grown from the crystal top surface ofmaterial 132. Material 142 may be epitaxially grown from the crystal topsurface of material 132 by epitaxial growth (e.g., heteroepitaxy growth)and may only grow from “seed” top surface of material 132 below thetrench top, but not grow from the sidewalls or STI top surfaces, similarto the description for growing material 122 from surface 103.

Material 142 may be a third layer of crystalline material that has orextends to height H1 defined by the vertical distance between topsurface 103 and a top surface of material 142. According to embodiments,growing or forming material 142 may include epitaxially growing a “finlayer” of a fin epitaxial material (e.g., material 142) from substratesurface 103 at a bottom of a trench 105 formed between shallow trenchisolation (STI) regions 107 and 108 having STI sidewalls 113 and 115defining a first width W1 and a first height H1 of the trench.

Material 142 may have a bottom surface having a (100) crystal orientedmaterial grown from material 132, and side surfaces having a (110)crystal oriented material along a direction parallel to sidewalls 113and 115. In some embodiments, crystaline defects may that existed inmaterial 122 or 132 near or along the sidewalls of the STI do not extendinto or to the top of material 142 (e.g., do not extend into height H1above height H3).

Material 142 may have a top surface having a (100) crystal orientation(Miller Index). Material 142 may have horizontal width extending acrossor over the trenches and top surfaces surfaces 116 and 117 of STIregions 107 and 108. Material 142 may have a length L1.

In some cases, when material 142 is a multi-stack, height H1 may be aheight of between 50 and 300 nanometers (m)). In some cases, whenmaterial 142 is a single layer, height H1 may be a height of between 20and 300 nanometers (nm). In some cases, H1 is approximately 50 nm.According to some embodiments, the difference in height between the topof material 132 and the top of material 142 may be 50, 100, or 200nanometers (nm).

The bottom surface of material 142 may have the same (100) crystalorientation as that of material 132 (e.g., at its top surface). In somecases, the bottom surface of material 142 may have the same crystallattice size as that of material 132 (e.g., at its top surface).Material 142 may be a relaxed material (e.g., have a non-strainedlattice) with respect to its interface with material 132 (e.g., at itstop surface). In some cases, material 142 has a same lattice constant asthe bottom of the material 122 or that of surface 103. In some cases,material 142 is lattice matched with respect to material 132 (e.g., atop surface of material 132). In some cases, material 142 is fullystrained with respect to material 132 (e.g., a top surface of material132). The strain may be tensile or compressive strain appropriate toincrease carrier mobility.

In some embodiments, FIG. 3 may also show material 142 polished orplanarized to height H1 above surface 103. The top surface of material142 may be polished to form a flat surface having a (100) crystal indexabove or at a height HI of top surface 155 of material 142. Top surface155 may have the same height as and be planar with top surfaces 116 and117. In some cases, after or as a result of polishing, materials 122,132 and 142 in trench 105 may be described as epitaxial region 145.Polishing or planarizing epitaxial material 142 may be performed bychemical, physical or mechanical polishing as known in the art to form atop planar surfaces 155 of material 142.

Epitaxial region 145 may have W1 and L1, and H1. In some cases,materials 122, 132 and 142 may be described as an “epitaxial region”; ora “stack” of epitaxial layers or materials (e.g., after polishing toheight H1). In some embodiments, materials 122, 132 and 142 in thetrench may be described as a single “epitaxial region” (e.g., as singleregion 145); or a single “stack” of epitaxial layers or materials (e.g.,after polishing to height H1). In some embodiments, material 122 or 132are optional and not formed in the trench, such as where material 142 isformed on layer 132 without layer 122, or material 142 is formed onlayer 122 without layer 132. In some embodiments, only material 122, 132or 142 is formed. In some embodiments, materials 122, 132 and/or 142 inthe trench, as described above, are referred to as a single region,layer or material.

According to some embodiments, W1 may be between 10 and 15 nanometers(nm); H1 may be 350 nanometers (rim); H2 may be 70 nanometers (nm); thedifference in height between the top of material 122 and the top ofmaterial 132 may be 200 nanometers (nm); and the difference in heightbetween the top of material 132 (e.g., height H3) and the top ofmaterial 142 (e.g., height H1) or epitaxial region 145 may be 50nanometers (nm). Also, L1 may be equal to W1.

FIG. 4 shows the semiconductor substrate of FIG. 1 after patterningepitaxial material formed in the trench, and after etching the STIregions to form an electronic device fin from a height of the fin layer(e.g., material 142) extending above etched top surfaces of the STIregions. FIG. 4 shows pattern or mask 160 formed on top surface 155 ofepitaxial region 145. In some cases, mask 160 has width W1 and a heightabove surface 155. Mask 160 may have a length L1. In sonic cases, mask160 is formed by or of photoresist alone, or a photoresist/oxidecombination; or a photoresist/nitride combination.

Mask 160 may have sidewalls 166 and 170 above or adjacent to sidewalls113 and 115. In some cases, inner sidewalls 166 and 170 may be planarsurfaces parallel to and aligned with (e.g., directly above) planarsidewalls 113 and 115. Mask 160 may also have inner sidewalls 166 and170 above surfaces 116 and 117. Sidewalls 166 and 170 may be planarsurfaces parallel to and above planar sidewalls 113 and 115, such asdescribed for sidewalls 113 and 115.

According to embodiments, material 142 may be patterned (e.g., protectedby mask 160), and STI regions 107 and 108 may be etched to formelectronic device fin 245 from height HF of the fin layer extendingabove etched top surfaces 216 and 217 of the STI regions. In some cases,top surface 155 of fin or device material 142 is patterned with mask160, and then top surfaces 116 and 117 of STI regions 108 and 107 areetched to remove thickness (e.g., height HF) of STI regions 108 and 107,to form electronic device fin 245 having height HF of the fin layer(e.g., material 142) extending above etched top surfaces 216 and 217 ofthe plurality of etched STI regions 208 and 207. Such etching may used a“timed” etch, such as an etch for a period of time known to removeheight HF of the STI regions; or may use another process that is know toperform such etching. Fin 245 may be or include an “exposed” device wellor gate layer extending or disposed height HF above the etched STIregions 208 and 207.

Fin 245 may be an epitaxially grown layer or fin a first epitaxialmaterial (e.g., to become a P- or N-type material) having verticalsidewalls 266 and 270 extending height HF above surfaces 216 and 217.Fin 245 has sidewalls 266 and 270 that may be planar surfaces parallelto and aligned with (e.g., directly below) planar sidewalls 166 and 170.In some cases, sidewalls 266 and 270 may be planar surfaces parallel toand above planar sidewalls 113 and 115. Sidewalls and top surfaces ofthe fin may be considered “exposed” after etching an before growth of amatial from these surfaces (e.g., such as growth a device channel orgate buffer layer).

In some cases, STI regions 107 and 108 are selectively etched withrespect to masks 160 to form fin 245. Regions 107 and 108 may be etchedby wet or dry etching to remove material 104 that is not protected by orbelow mask 160. Etching regions 107 and 108 may include descriptionsabove for etching material 104 to form STI regions 107 and 108. In somecases, regions 107 and 108 may be etched using a wet etch (e.g., of HF)or a dry etch to remove only or not more than height HF of the materialof regions 107 and 108. In some cases, STI regions 108 and 107 aresimultaneously etched. such as during processing that simultaneouslyeffects, is applied to, or removes material of STI regions 108 and 107.

Fin 245 may have width W1, height HF above height H3, and length L1. Insome cases the width W1, height HF and length L1 of fin 245 are equal towidth W1, height H1-H3, and length L1 of region 145. In some cases,height HF may be less than H1-H3, such as due to (1) etching less thanheight HF of STI regions 108 and 107, and/or (2) polishing of material142 to less than height D1 prior to forming mask 160. In some cases, theheight HF and length L1 of fin 245 are equal to those of region 145, butthe width and length are less than that of region 145 due to etchingremoving some of the fin width and length. In some cases, fin 245 may bedefined by exposed the top surface 155 after removal of mask 160; andsidewalls 270 and 266 of epitaxial region 145.

In some cases, height HF may be a height of between 25 and 100nanometers (nm). In some cases, height HF may be a height of between 30and 70 nanometers (nm). In some cases. HF is approximately 50 nm.

FIG. 5 shows the semiconductor substrate of FIG. 1 after forming a firstconformal thickness of a first conformal epitaxial “cladding” materialgrown from sidewall surfaces and a top surface of the electronic devicefin. FIG. 5 shows fin 245 of FIG. 4 after removing mask 160 to exposetop surface 155, and growing conformal thickness T1 of conformalepitaxial “cladding” 521 of expitaxial material 522 from sidewallsurfaces 266 and 270, and from top surface 155 of the electronic devicefin 245.

Mask 160 may be etched by a dry etching process that removes thevertical thickness of Mask 160. In some cases, the etch may be ananisotropic etch. In some cases, the etch may be a subtractive etch,such as to etch away mask 160, with the exception of other materials,such as material 142, 207 and 208. In some cases, the etch may useChlorine or another acidic dry chemistry. In some cases, mask 160 isselectively etched using a wet etch (e.g., of HF) or a dry etch toremove all of mask 160.

In some embodiments. material 522 is formed or grown as a “cladding”layer or material grown from sidewall surfaces 266 and 270 to formsidewall surfaces 566 and 570; and grown from top surface 155 to formtop surface 555. Material 522 (e.g., Sidewall surfaces 566 and 570) maynot grow from, but may touch surfaces 216 and 217.

In some cases, a “cladding” material (e.g., material 522) may be“selectively” grown only from a desired single crystal material (e.g,material 142 in this case) but not from other polycrystal, dielectric,oxide, nitride or amorphouse exposed materials (e.g., that are not thedesired or are not a single crystal material). In some cases, a“cladding” material (e.g., material 522) may be “selectively” grown onlyfrom a desired single crystal material (e.g, material 142 in this case)by masking or forming oxide layers over materials that it is not desiredto have the “cladding” material form or grow from.

According to some embodiments, material 522 may be formed by epitaxialgrowth (e.g., heteroepitaxy growth) using atomic layer epitaxy (ALE),chemical vapor deposition (CVD), Metal-Organic Chemical VapourDeposition (MOCVD) or Metal-Organic vapour phase epitaxy (MOVPE), andmay only grow from “seed” sidewall and top surfaces of material 142. Insome cases, material 522 may be formed by epitaxial growth (e.g.,heteroepitaxy) using molecular beam epitaxy (MBE), or migration enhancedepitaxy (MEE) and may only grow from “seed” sidewall and top surfaces ofmaterial 142. Material 522 may be an epitaxially grown crystal material,grown from a single crystal surfaces of material 142.

Material 522 may be formed on or touching material 142. Material 522 maybe formed to a conformal thickness (e.g., a thickness increasing the“height” on the top surface and “width” on the sidewalls) over fin 245.The conformal thickness T1 may be between 1 and 10 nanometers (nm). Insome cases the conformal thickness T1 is approximately 2 nm. In somecases the conformal thickness T1 is approximately 5 nm. According tosome embodiments, forming material 522 includes epitaxially cladding orgrowing material 522 along, across, touching or against the sidewallsurfaces and the top surface of the electronic device fin 245.

Material 522 may have width equal to (W1+2(T1)), height equal to(HF+T1), and length L1. In some cases, material 522 may be defined byexposed the top surface 555; sidewalls 566 and 570 of the epitaxialregions. In some cases, sidewalls 566 and 570 may be planar surfacesparallel to and aligned with (e.g., directly adjacent to and wider thanby thickness T1) planar sidewalls 266 and 270.

In some cases, material 522 may have a length of L1, such as wherematerial 142 is a device buffer material, and material 522 is a channelmaterial formed over all of a total length of the buffer material. Inthis case, the sidewall and top surfaces of material 142 may not bemasked or patterned during cladding of material 522 onto material 142.

In some cases, material 522 may have a length of less than L1, such aswhere material 142 is a device channel material, and material 522 is agate buffer material or a junction region material (of one or twojunction regions) formed over a only portion or two portions) of a totallength of the channel material 142. If material 522 is a gate buffermaterial, a gate dielectric or electrode material may be clad from orformed over the gate buffer material.

In this case, the sidewall and top surfaces of material 142 along alength of material 142 (or two lengths) may be masked or patternedduring cladding of material 522 onto material 142 so that material 522is clad along only the desired portion (or two portions) of a totallength of the channel material 142.

In some cases, material 522 is a gate buffer material that helps preventdefects between channel material 142 and a high K gate dielectricmaterial formed over material 522 (e.g., for a tri-gate device) byhaving reduced broken bonds at the interface between material 142 and522 (e.g., where material 522 is grown from material 142).

In some cases, material 522 is a gate buffer material and a high K gatedielectric or electrode material of between 2 and 3 nm in conformalthickness is formed over material 522 (e.g., for a tri-gate device),such as by cladding as described herein or by another process. In somecases, the high K gate dielectric or electrode material is or includestantalum, SiO, HfO, and/or AlO.

In some cases, material 522 is a gate buffer material and a high K gatedielectric and a gate electrode material of between 10 and 30 nm inconformal thickness is formed over the gate dielectric material (e.g.,for a tri-gate device), such as by cladding as described herein or byanother process. In some cases, the gate electrode material is orincludes titanium nitride, and/or tantalum nitride.

FIG. 6A shows the semiconductor substrate of FIG. 1 after forming asecond and a third conformal thickness of a second and a third conformalepitaxial “cladding” material grown from sidewall surfaces and a topsurface of the first conformal thickness. FIG. 6B is a schematic topperspective cross section view of examples of FIG. 6A, such as wherematerial 522 is a device gate buffer material formed over a portion of atotal length of the channel material 142; material 622 is agatedielectric material or a gate electrode material formed over material522; and material 632 is a junction region material (of two junctionregions) formed over two portions of a total length of the channelmaterial 142. FIG. 6C is a schematic top perspective cross section viewof examples of FIG. 6A, such as where material 522 is a device channelmaterial; material 622 is agate dielectric material or a gate electrodematerial formed over a portion of a total length of material 522; andmaterial 632 is a junction region material (of two junction regions)formed over two other portions of a total length of the channel material522.

FIGS. 6A-C shows conformal thickness 521 of material 522 of FIG. 5 aftergrowing conformal thickness T2 of conformal epitaxial “cladding” 621 ofexpitaxial material 622 from sidewall surfaces 566 and 570, and from topsurface 555 over electronic device fin 245. In some embodiments,material 622 is formed or grown from sidewall surfaces 566 and 570 toform sidewall surfaces 666 and 670; and formed or grown from top surface555 to form top surface 655. Material 622 (e.g., sidewall surfaces 666and 670) may not grow from, but may touch surfaces 216 and 217. In somecases, material 622 is a “cladding” material that is “selectively” grownfrom material 522, similar to the description above of material 522being a “cladding” material that is “selectively” grown from material142.

According to some embodiments, material 622 may be formed by epitaxialgrowth (e.g., heteroepitaxy growth) using ALE, CVD, MOCVD, MOVPE, MBE,or MEE and may only grow from “seed” sidewall and top surfaces ofmaterial 522. Material 622 may be an epitaxially grown crystal material,grown from a single crystal surfaces of material 522.

Material 622 may be formed on or touching material 522. Material 622 maybe formed to a conformal thickness T2 over material 522. The conformalthickness T2 may be between 1 and 10 nanometers (nm). In some cases theconformal thickness T2 is approximately 2 nm. In some cases theconformal thickness T2 is approximately 5 nm.

Material 622 may have width equal to (W1+2(T1)+2(T2)), height equal to(HF+T1+T2), and length L1. In some cases, material 622 may be defined byexposed the top surface 655; sidewalls 666 and 670 of the epitaxialregions. In some cases, sidewalls 666 and 670 may be planar surfacesparallel to and aligned with (e.g., directly adjacent to and wider thanby thickness T2) planar sidewalls 566 and 570.

In some cases, material 622 may have a length of less than L1, such aswhere material 522 is a device gate buffer material, and material 622 isa gate dielectric material or a gate electrode material formed over aonly portion of a total length of the channel material 142 (e.g., seeFIG. 6B). If material 622 is a gate buffer material, a gate dielectricor electrode material may be clad from or formed over the gate buffermaterial.

In some cases, material 622 may have a length of less than L1, such aswhere material 522 is a device channel material, and material 622 is agate dielectric material (e.g., see FIG. 6C), a gate electrode materialor a junction region material (of one or two junction regions) formedover a only portion (or two portions) of a total length of the channelmaterial 522.

In some case, the sidewall and top surfaces of material 522 along alength of material 522 (or two lengths) may be masked or patternedduring cladding of material 622 onto material 522 so that material 522is clad along only the desired portion (or two portions) of a totallength of the channel material 522.

FIGS. 6A-C show growing conformal thickness T3 of conformal epitaxial“cladding” 631 of expitaxial material 632 from: (1) sidewall surfaces266 and 270, and from top surface 555 of material 142 over electronicdevice fin 245 (e.g., see FIG. 6B); or (2) sidewall surfaces 566 and570, and from top surface 555 of material 522 over electronic device fin245 (e.g., see FIG. 6C). In some embodiments, material 632 is formed orgrown from sidewall surfaces of material 142 or 522 to form sidewallsurfaces 676 and 680; and formed or grown from top surfaces of material142 or 522 to form top surface 675. Material 632 (e.g., sidewallsurfaces 676 and 680) may not grow from, but may touch surfaces 216 and217. In some cases, material 632 is a “cladding” material that is“selectively” grown from material 142 or 522, similar to the descriptionabove of material 522 being a “cladding” material that is “selectively”grown from material 142.

According to some embodiments, material 632 may be formed by epitaxialgrowth (e.g., (heteroepitaxy growth) using ALE, CVD, MOCVD, MOVPE, MBE,or MEE and may only grow from “seed” sidewall and top surfaces ofmaterial 142 or 522. Material 632 may be an epitaxially grown crystalmaterial grown from a single crystal surfaces of material 142 or 522.

Material 632 may be formed on or touching material 142 or 522, but nottouching or contacting material 622. Material 632 may be formed to aconformal thickness T3 over material 142 or 522. The conformal thicknessT3 may be between 5 and 20 nanometers (nm). In some cases the conformalthickness T3 is approximately 10 nm. In some cases the conformalthickness T3 is approximately 15 nm.

Material 632 may have width equal to (W1+2(T1)+2(T2)+2(T3)), heightequal to (HF+T1+T2+T3), and length L1. In some cases, material 632 maybe defined by exposed the top surface 655; sidewalls 666 and 670 of theepitaxial regions. In some cases, sidewalls 676 and 680 may be planarsurfaces parallel to and aligned with (e.g., directly adjacent to andwider than by thickness T3) planar sidewalls 566 and 570.

In some cases, such as shown in FIG. 6B, material 632 may have a lengthof less than L1, such as where material 522 is a gate buffer materialformed over a only portion of a total length of the channel material142, material 622 is agate dielectric material, or a gate electrodematerial formed material 522, and material 632 is a junction regionmaterial (of two junction regions) formed over a only a portion (or twoportions) of a total length of the channel material 142. In this case,the sidewall and top surfaces of material 142 along a two lengths ofmaterial 142 may be masked or patterned during cladding of material 632onto material 142 so that material 142 is clad along only the desiredportion (or two portions) of a total length of the channel material 142.

In some cases, such as shown in FIG. 6C, material 632 may have a lengthof less than L1, such as where material 522 is a device channelmaterial, and material 632 is a gate dielectric material, a gateelectrode material or a junction region material (of one or two junctionregions) formed over a only portion (or two portions) of a total lengthof the channel material 522.

In this case, the sidewall and top surfaces of material 522 along alength of material 522 (or two lengths) may be masked or patternedduring cladding of material 632 onto material 522 so that material 522is clad along only the desired portion (or two portions) of a totallength of the channel material 522.

According to some embodiments, material 622 may be a gate dielectricmaterial or a gate electrode material formed over a only portion of atotal length of the channel material 522; and material 632 representstwo sections (e.g., source and drain) of junction region material formedover two other portions of the total length of the channel material 522(e.g., see FIG. 6C).

In this case, the sidewall and top surfaces of material 522 may bepatterned to clad material 622 onto material 522, and then material 622may be subsequently patterned during cladding of material 632 ontomaterial 522 (e.g., see FIG. 6C). It can be appreciated that for someembodiments, this order can be reversed.

According to a first set of exemplary embodiments, material 122 is a“buffer” material having a lattice constant between that of the materialthat material 122 is grown from (e.g., surface 103, such as of Si) andthat of the material that is grown from material 122 (e.g., material 132grown from or formed on layer 122). In some embodiments, layer 122 is asingle layer, while in others, it is multiple layers. In some cases,layer 122 is a graded buffer layer having a concentration of Ge thatincreases from zero percent at surface 103 to 30 percent at its topsurface. In some cases, layer 122 is a selectively grown epitaxiallayer.

In some cases, material 122 is a layer of InP material (e.g., 50 percentIn, and 50 percent P) such as for an N-type device formed from fin 245;or is a layer of SiGe material (e.g., 70 percent Si, and 30 percent Ge)such as for an P-type device formed from fin 245.

In some cases, layer 122 is a selectively grown epitaxial layer that isgrown from portions of surface 103 only in trenches, but not from STImaterial or surfaces forming the trenches. In some cases, layer 122represents separate selectively grown epitaxial layers that are grownfrom portions of surface 103 in two adjacent trenches, but not from STImaterial or surfaces forming the trenches, such as will be describedbelow for FIGS. 6-12. In some cases, layer 122 is a blanket (e.g.,non-selective) epitaxial layer grown from all of surface 103 below STImaterial and two different trenches, such as will be described below forFIGS. 13-19.

In some cases, material 132 is a relaxed “buffer” material having alattice constant the same as or close to that of the material that isgrown from material 132 (e.g., material 142 grown from or formed onlayer 132). In some embodiments, layer 132 is a single layer, while inothers, it is multiple layers. In some cases, layer 132 is a gradedbuffer layer having a concentration that increases from its bottom toits top surface. In some cases, layer 132 is an ART epitaxial bufferlayer as known in the art. In some cases, layer 132 is a selectivelygrown epitaxial layer. In some cases, material 132 is a layer of InAlAsmaterial (e.g., 52 percent In, 48 percent Al) such as for an N-typedevice formed from fin 245; or is a layer of SiGe material (e.g., 30percent Si, and 70 percent Ge) such as for an P-type device formed fromfin 245. In some cases the layer of InAlAs is 70 percent In and 30percent Al; or In_(x)Al_(1-x)As where x=0.7; or 70% of In and 30% of Alfor group III side and 100% for As which is group V material.

According to some embodiments, material 132 and 142 are the samematerial. In such cases, material 132 and 142 may be the same materialgrown during the same growth process or time. In some of these cases,material 142 is a buffer material upon with the device material orlayers are formed cladding materials (e.g., material 522 is a channelmaterial). In some cases, layer 142 is free from crystaline defects thatare prevented by the ART of growing layers 122, 132 and 142 in ARTtrench 105.

According to some embodiments, material 132 and 142 are differentmaterials. In such cases, material 132 and 142 may be differentmaterials grown during different growth processes or at different times.In these cases, material 142 may be a device material or layer (e.g.,material 142 is a channel material). According to some embodiments,material 142 may be channel material or layer, such as for a tri-gatedevice having the channel conducting charges along the sidewall and topmaterial of material 142; and material 522 may be a gate region or layer(e.g., gate dielectric and gate electrode), such as for a tri-gatedevice having the gate biasing the conducted charges along the sidewalland top material of material 142. In some cases, material 142 is asingle layer of Ge, InGaAs or InAs material.

In some cases, material 142 is a channel layer of InGaAs material (e.g.,70 percent InAs and 30 percent GaAs; or 70% of In and 30% of Ga forgroup III side and 100% for As which is group V material; orIn_(x)Ga_(1-x)As where x=0.53) and material 522 is an InP cladding gatebuffer material for gate dielectric layer formed on a portion of thelength of layer 522, such as such as for an N-type device formed fromfin 245. In some cases, material 142 is a channel layer of Ge devicematerial and material 522 is a Si cladding gate buffer material for gatedielectric layer formed on a portion of a length of layer 522, such assuch as for an P-type device formed from fin 245. In some cases, layer142 is free from crystaline defects that are prevented by the ART ofgrowing layers 122, 132 and 142 in ART trench 105. In some cases,material 142 may be another buffer material upon which a device materialor layer is clad (e.g., as channel material 522). In these cases,material 142 may extend below surfaces 216 and 217, such as where H3 isless than shown in the figures and HF extends below surfaces 216 and217.

In some cases, material 122 is a layer of SiGe material (e.g., 70percent Si, and 30 percent Ge) such as a “buffer” material; material 132is a layer of SiGe material (e.g., 30 percent Si, and 70 percent Ge)such as a relaxed “buffer” material; and layer 142 is a channel layerover the total length of material 142 of either (1) a layer of InPmaterial (e.g., 50 percent In, and 50 percent P), or (2) a layer ofInAlAs material (e.g., 50 percent In, 25 percent Al and 25 percent As)such as such as for an N-type device formed from fin 245. In some casesthe layer of InAlAs is 70 percent InAs and 30 percent AlAs; orIn_(x)Al_(1-x)As where x=0.7; or 70% of In and 30% of Al for group IIIside and 100% for As which is group V material.

According to some embodiments, material 622 is grown on material 522,and material 632 is grown on material 522. In such cases, material 142may be a buffer material; material 522 may be channel material or layer,such as for a tri-gate device having the channel conducting chargesalong the sidewall and top material of material 522; material 622 may bea gate region or layer (e.g., gate dielectric and gate electrode), suchas for a tri-gate device having the gate biasing the conducted chargesalong a portion of the length of the sidewall and top material ofmaterial 522; and material 632 may be or include two junction regions orlayers on or touching material 522, such as for a tri-gate device havingseparate source and drain regions at or across different portions oflength L1 along the sidewall and top material of material 522.

According to some embodiments, material 622 is grown on material 522,but material 632 is not grown on material 622. In such cases, material142 may be a buffer material; material 522 may be channel material orlayer, such as for a tri-gate device having the channel conductingcharges along the sidewall and top material of material 522; andmaterial 622 may be (1) a gate region or layer (e.g., gate dielectricand gate electrode), such as for a tri-gate device having the gatebiasing the conducted charges along a portion of the length of thesidewall and top material of material 522, or (2) two junction regionsor layers on or touching material 522, such as for a tri-gate devicehaving separate source and drain regions at or across different portionsof length L1 along the sidewall and top material of material 522.

In some cases, material 522 is a cladding layer of doped N-type InGaAschannel material (e.g., 70 percent InAs and 30 percent GaAs; or 70% ofIn and 30% of Ga for group III side and 100% for As which is group Vmaterial; or In_(x)Ga_(1-x)As where x=0.53); material 622 is gatedelectric or electrode of InP cladding material (e.g., 50 percent In,and 50 percent P) on or over an N-type channel formed of material 522clad on fin 245; and material 632 represents two junction regions ofInGaAs material (e.g., 70 percent InAs and 30 percent GaAs; or 70% of Inand 30% of Ga for group III side and 100% for As which is group Vmaterial; or In_(x)Ga_(1-x)As where x=0.53) as cladding material grownfrom channel material 142.

In some cases, material 522 is a cladding layer of doped P-type Gechannel material; and material 622 is gate delectric or electrode of Sicladding material on or over an P-type channel formed of material 522clad on fin 245. In addition, in some cases, material 632 represents twojunction regions of titanium and/or aluminum based junction material ascladding material grown from channel material 142.

According to a second set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trench 105, but not from STI material or surfaces forming thetrenches.

In these cases, material 122 is a layer of InP material (e.g., 50percent In, and 50 percent P) such as for an N-type channel formed ofmaterial 142 in fin 245. In these cases, material 132 is a relaxed“buffer” material having a lattice constant the same as or close to thatof material 142. In these cases, material 132 is a layer of InAlAsmaterial (e.g., 50 percent In, 25 percent Al and 25 percent As) such asfor an N-type channel formed of material 142 in fin 245. In some casesthe layer of InAlAs is 70 percent InAs and 30 percent AlAs; orIn_(x)Al_(1-x)As where x=0.7; or 70% of In and 30% of Al for group IIIside and 100% for As which is group V material.

In these cases, material 142 is a channel material or layer for atri-gate device having the channel conducting charges along the sidewalland top material of material 142; and material 522 is a gate region orlayer (e.g., gate dielectric and gate electrode), such as for a tri-gatedevice having the gate biasing the conducted charges along the sidewalland top material of material 142. In these cases, material 142 is alayer of doped N-type InGaAs channel material (70 percent InGa and 30percent GaAs; or 70% of In and 30% of Ga for group III side and 100% forAs which is group V material; or In_(x)Ga_(1-x)As where x=0.53). Inthese cases, material 522 is gate buffer layer of InP cladding material(e.g., 50 percent In, and 50 percent P) grown from a portion of thelength of the N-type channel formed of material 142 in fin 245, and uponwhich a gate dielectric layer may be formed, such as such as for anN-type device formed from or on fin 245.

According to a third set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trench 105, but not from STI material or surfaces forming thetrenches. In these cases, material 122 is a layer of SiGe material(e.g., 70 percent Si, and 30 percent Ge) such as for a P-type channelformed of material 142 in fin 245. In these cases, material 132 is arelaxed “buffer” material having a lattice constant the same as or closeto that of material 142. In these cases, material 132 is a layer of SiGematerial (e.g., 30 percent Si, and 70 percent Ge such as for a P-typechannel formed of material 142 in fin 245.

In these cases, material 142 is a channel material or layer for atri-gate device having the channel conducting charges along the sidewalland top material of material 142; and material 522 is agate region orlayer (e.g., gate dielectric and gate electrode), such as for a tri-gatedevice having the gate biasing the conducted charges along the sidewalland top material of material 142. In these cases, material 142 is alayer of doped P-type Ge channel material. In these cases, material 522is gate buffer layer of Si cladding material grown from a portion of thelength of the P-type channel formed of material 142 in fin 245, and uponwhich a gate dielectric layer may be formed, such as such as for anP-type device formed from or on fin 245.

According to a fourth set of examplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trench 105, but not from STI material or surfaces forming thetrenches. In these cases, material 122 is a layer of InP material (e.g.,50 percent In, and 50 percent P) such as for an N-type channel formed ofmaterial 522 in fin 245.

In these cases, material 132 and 142 are the same material (e.g.,material 132/142). In these cases, material 132/142 is a relaxed“buffer” material having a lattice constant the same as or close to thatof material 522 clad on fin 245. In these cases, material 132/142 is alayer of InAlAs material (e.g., 50 percent In, 25 percent Al and 25percent As) such as for an N-type channel formed of material 522 clad onfin 245. In some cases the layer of InAlAs is 70 percent InAs and 30percent AlAs; or In_(x)Al_(1-x)As where x=0.7; or 70% of In and 30% ofAl for group III side and 100% for As which is group V material.

In such cases, material 522 is a channel material or layer, such as fora tri-gate device having the channel conducting charges along thesidewall and top material of material 522; material 622 is a gate regionor layer (e.g., gate dielectric and gate electrode), such as for atri-gate device having the gate biasing the conducted charges along thesidewall and top material of material 522; and material 632 includesjunction regions or layers on or touching material 522, such as for atri-gate device having separate source and drain region at or acrossdifferent portions of length L1 along the sidewall and top material ofmaterial 522. In these cases, material 522 is a cladding layer of dopedN-type InGaAs channel material (e.g., 70 percent InAs and 30 percentGaAs; or 70% of In and 30% of Ga for group III side and 100% for Aswhich is group V material; or In_(x)Ga_(1-x)As where x=0.53).

In these cases, material 622 is gate delectric or electrode of InPcladding material (e.g., 50 percent In. and 50 percent P) on or over anN-type channel formed of material 522 clad on fin 245. In these cases,material 632 represents two junction regions of InGaAs material (e.g.,70 percent InAs and 30 percent GaAs; or 70% of In and 30% of Ga forgroup III side and 100% for As which is group V material; orIn_(x)Ga_(1-x)As where x=0.53) as cladding material grown from channelmaterial 142.

According to a fifth set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trench 105, hut not from STI material or surfaces forming thetrenches. In these cases, material 122 is a layer of SiGe material(e.g., 70 percent Si, and 30 percent Ge) such as for a P-type channelformed of material 522 in fin 245.

In these cases, material 132 and 142 are the same material (e.g.,material 132/142). In these cases, material 132/142 is a relaxed“buffer” material having a lattice constant the same as or close to thatof material 522 clad on fin 245. In these cases, material 132/142 is alayer of SiGe material (e.g., 30 percent Si, and 70 percent Ge) such asfor a P-type channel formed of material 522 clad on fin 245.

In such cases, material 622 is grown on material 522, but material 632is not grown on material 622. In such cases, material 142 is a buffermaterial; material 522 is a channel material or layer, such as for atri-gate device having the channel conducting charges along the sidewalland top material of material 522; and material 622 may be a gate regionor layer (e.g., gate dielectric and gate electrode), such as for atri-gate device having the gate biasing the conducted charges along thesidewall and top material of material 522.

In these cases, material 522 is a cladding layer of doped P-type Gechannel material. In these cases, material 622 is gate delectric orelectrode of Si cladding material on or over an P-type channel formed ofmaterial 522 clad on fin 245.

According to a sixth set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trench 105, but not from STI material or surfaces forming thetrenches. In these cases, material 122 is a layer of SiGe material(e.g., 70 percent Si, and 30 percent Ge) such as for an N-type channelformed of material 522 clad on fin 245.

In these cases, material 132 is a relaxed “buffer” material having alattice constant the same as or close to that of material 522. In thesecases, material 132 is a layer of SiGe material (e.g., 30 percent Si,and 70 percent Ge) such as for an N-type channel formed of material 522clad on fin 245.

In these cases, material 142 may be another buffer material upon which adevice material or layer is clad (e.g., as channel material 522). Inthese cases, material 142 may extend below surfaces 216 and 217, such aswhere H3 is less than shown in the figures and HF extends below surfaces216 and 217.

In these cases, layer 142 is either (1) a layer of InP material (e.g.,50 percent In, and 50 percent P), or (2) a layer of InAlAs material(e.g., 50 percent In, 25 percent Al and 25 percent As) such as for anN-type channel formed of material 522 clad on fin 245. In some cases thelayer of InAlAs is 70 percent InAs and 30 percent AlAs; orIn_(x)Al_(1-x)As where x=0.7; or 70% of In and 30% of Al for group IIIside and 100% for As which is group V material.

In such cases, material 522 is a channel material or layer, such as fora tri-gate device having the channel conducting charges along thesidewall and top material of material 522; material 622 is a gate regionor layer (e.g., gate dielectric and gate electrode), such as for a trigate device having the gate biasing the conducted charges along thesidewall and top material of material 522; and material 632 includesjunction regions or layers on or touching material 522, such as for atri-gate device having separate source and drain region at or acrossdifferent portions of length L1 along the sidewall and top material ofmaterial 522.

In these cases, material 522 is a cladding layer of doped N-type InGaAschannel material (e.g., 70 percent InAs and 30 percent GaAs; or 70% ofIn and 30% of Ga for group III side and 100% for As which is group Vmaterial; or In_(x)Ga_(1-x)As where x=0.53). In these cases, material622 is gate delectric or electrode of InP cladding material (e.g., 50percent In, and 50 percent P) on or over an N-type channel formed ofmaterial 522 clad on fin 245. In these cases, material 632 representstwo junction regions of InGaAs material (e.g., 70 percent InAs and 30percent GaAs; or 70% of In and 30% of Ga for group III side and 100% forAs which is group V material; or In_(x)Ga_(1-x)As where x=0.53) ascladding material grown from channel material 142.

FIG. 7 shows the semiconductor substrate of FIG. 1 after forming STIregions and two trenches between the STI regions. FIG. 7 shows trenches105 and 106 defined between STI regions 107, 108 and 110 and surface103. Region 110 and trench 106 may be formed as described above forforming regions 107, 108 and trench 105. Trenches 105 and 106 may beadjacent trenches that are next to each other without other device finsformed in or within region 108 between trenches 105 and 106.

STI region 108 has sidewalls 112 and 115, and has top surface 116. STIregion 110 has sidewall 114 and top surface 118. Sidewalls 112 and 114may be vertical planar surfaces perpendicular to (e.g., at a right anglewith respect to) horizontal planar surfaces surface 103 and horizontalplanar surfaces 116 and 118. The sidewalls may comprise or be STImaterial 104. STI regions 108 and 110 may have a width WI defined by thehorizontal distance between their sidewalls. STI region 108 may havewidth W1 defined by the horizontal distance between sidewall 115 ofregion 107 and side at sidewall 112 of region 108. STI region 110 mayhave height H1 defined by the vertical distance between top surface 103and top surface 118. STI region 110 may have a length L1 defined as thelength going into the page and along sidewall 114.

Trench 106 may be defined by the sidewalls of regions 108 and 110. Morespecifically FIG. 7 shows trench 106 defined by or having a side atsidewall 112 of region 108, a side at sidewall 114 of region 110, abottom at top surface 103, and a top (e.g., opening or corners) adjacentto top surfaces 116 or 118. Trench 106 may include surface 103 ofmaterial 102 exposed at the bottom of the trench, such as a planar orplanarized surface of crystal material. In some cases. trench 106 isdefined by additional sidewalls of other STI regions, such as a frontand back STI having sidewall similar to sidewalls 112 and 114, and topsurfaces similar to surfaces 117 or 118, but defining length L of trench106.

Trench 106 may have width W1 defined by the horizontal distance betweensidewall 112 of region 108 and side at sidewall 114 of region 110. Insome cases W1 is three times the pitch of the fins formed in theepitaxial regions, such as three times the horizontal pitch between themidpoint of fins 1145 and 1146, or between that of fins 1845 and 1846(e.g., see FIGS. 11 and 18). Trench 106 may have height HI defined bythe vertical distance between top surface 103 and top surface 117 or118.

Trench 106 may have a length L1 defined as the length going into thepage and along sidewall 112 or 114. In some cases L1 is two times thepitch of the gates of transistor devices formed on the fins, such as twotimes the pitch between the gates of transistor devices formed on fins1145 and 1146, or fins 1845 and 1846 (e.g., see FIGS. 11 and 18).

FIG. 7 shows trenches 105 and 106 defined between STI regions 107, 108and 110 and surface 103. However it is contemplated that more, similartrenches and STI regions may exist on substrate 101 (e.g., such as atleast hundreds or hundreds of thousands). FIG. 7 shows the semiconductorsubstrate of FIG. 1 after forming epitaxial material 122 in the trenchesbetween the STI regions. FIG. 3 shows a first layer of material 122epitaxially grown from surface 103 in trenches 105 and 106. Material 122may be epitaxially grown from the crystal surface of substrate surface103 in trench 106 with respect to STI material surfaces 112, 114, 116and 118, similar to the description above for growing material 122 intrench 105 with respect to STI material surfaces 113, 115, 117 and 116,respectively.

FIG. 8 shows the semiconductor substrate of FIG. 1 after forming a maskover material 122 in trench 106, and forming second epitaxial material142 in the trench 105. FIG. 8 shows pattern or mask 860 formed on topsurfaces of material 122 in trench 106, sidewall surfaces of trench 106,and at least a portion of top surfaces 116 and 118. In some cases, mask860 has width across top surfaces 116 and 118 that is greater than W1,and a height above surface 103 that is greater than H1. Mask 860 mayhave a length L1. In some cases, mask 860 is formed by or of photoresistalone, or a photoresist/oxide combination; or a photoresist/nitridecombination. Mask 860 may have sidewalls above top surfaces 116 and 118,and may have a planarized top surface. Mask 860 may seal off trench 106so that after forming mask 860, material grown or deposited in trench105 does not enter trench 106.

FIG. 8 shows a second layer of material 142 epitaxially grown from a topsurface of material 122. Material 142 may be epitaxially grown from thecrystal top surface of material 122. Material 142 may be a “device”layer, such as a layer on or in which circuity devices are formed, asknown in the art. Such devices may include devices described herein.

Material 142 may be formed by epitaxial growth (e.g., heteroepitaxy)from material 122, similar to descriptions above for growing material142 from material 132. Material 142 may be epitaxially grown from thecrystal surface of material 132 in trench 105 with respect to STImaterial surfaces 113, 115, 116 and 117, similar to the descriptionabove for FIG. 3. Material 142 may be grown to height greater than H1above surface 103.

The bottom surface of material 142 may have the same (100) crystalorientation as that of material 122 (e.g., at its top surface). In somecases, the bottom surface of material 142 may have the same crystallattice size as that of material 122 (e.g., at its top surface).Material 142 may be a relaxed material (e.g., have a non-strainedlattice) with respect to its interface with material 122 (e.g., at itstop surface). In some cases, material 142 has a same lattice constant asthe bottom of surface 103. In some cases, material 142 is latticematched with respect to a top surface of material 122. In some cases,material 142 is fully strained with respect to a top surface of material122. The strain may be tensile or compressive strain appropriate toincrease carrier mobility.

FIG. 9 shows the semiconductor substrate of FIG. 1 after polishing andpatterning epitaxial material 142 formed in trench 105, removing mask860, forming mask 960, and forming a second and third epitaxial materialin trench 106. In some embodiments, FIG. 9 may also show material 142polished or planarized to height H1 above surface 103. In some casespolished material 142 has height H1-H2. According to some embodiments,the difference in height between the top of material 122 and the top ofpolished material 142 may be 100, 200, or 300 nanometers (nm). In someembodiments, materials 122 and/or polished material 142 in the trench,as described above, are referred to as a single region, layer ormaterial. The top surface of material 142 may be polished to form a flatsurface having a (100) crystal index above or at a height HI of topsurface 155 of material 142, such as described for FIG. 4. In somecases, after or as a result of polishing, material 142 in trench 105 maybe described as epitaxial region 145.

FIG. 9 also shows epitaxial region 945 after removing mask 860 to exposetop surface 155. Mask 860 may be etched by a dry etching process thatremoves the vertical thickness of Mask 860 as described for removingmask 160. In some cases, mask 860 is removed by or during polishingabove of material 142 to height H1.

After polishing material 142, FIG. 9 shows pattern or mask 960 formed ontop surfaces of polished material 142 in trench 105, and at least aportion of top surfaces 116 and 117. In some cases, mask 960 has widthacross top surfaces 116 and 117 that is greater than W1, and a heightabove surface 103 that is greater than H1. Mask 960 may have a lengthL1. In some cases, mask 960 is formed similar to forming mask 860. Mask960 may seal off trench 105 and material 142 so that after forming mask960, material grown or deposited in trench 106 does not enter trench 105or touch material 142.

FIG. 9 shows a second layer of material 130 epitaxially grown from a topsurface of material 122. Material 130 may be grown to height H3 abovesurface 103. Material 130 may be formed by epitaxial growth (e.g.,heteroepitaxy) from material 122, similar to descriptions above forgrowing material 132 from material 122 for FIG. 3. Material 130 may beepitaxially grown from the crystal surface of material 122 in trench 106with respect to STI material surfaces 112, 114, 116 and 118, similar tothe description above for FIG. 3 and growing material 132 in trench 105with respect to STI material surfaces 113, 115, 117 and 116,respectively. Material 130 may be a “buffer” layer, such as describedfor material 132.

FIG. 9 shows a third layer of material 140 epitaxially grown from a topsurface of material 132. Material 140 may be grown to height greaterthan above surface 103. In some cases material 142 have height H1-H3.Material 140 may be formed by epitaxial growth (e.g., heteroepitaxy)from material 130, similar to descriptions above for growing material142 from material 132 for FIG. 3. Material 140 may be epitaxially grownfrom the crystal surface of material 130 in trench 106 with respect toSTI material surfaces 112, 114, 116 and 118, similar to the descriptionabove for FIG. 3 and growing material 142 in trench 105 with respect toSTI material surfaces 113, 115, 117 and 116, respectively.

In some cases, material 140 may be a “device” layer, such as a layer onor in which circuity devices are formed, as known in the art, such asdescribed for material 142. Such devices may include devices describedherein. In some cases, material 140 may be a “buffer” layer, such as alayer on or over which a “device” layer will be formed, as known in theart, such as described for material 142.

Material 140 may have a bottom surface having a (100) crystal orientedmaterial grown from material 130, and side surfaces having a (110)crystal oriented material along a direction parallel to sidewalls 112and 114. In some embodiments, crystaline defects may that existed inmaterial 122 or 130 near or along the sidewalls of the STI do not extendinto or to the top of material 140 (e.g., do not extend into height H1above height H3).

FIG. 10 shows the semiconductor substrate of FIG. 1 after polishingepitaxial material 140 and removing mask 960 to form epitaxial region1046. Regions 945 and 1046 may be epitaxially grown regions of a firstepitaxial material (e.g., to become a P- or N-type material) on thesubstrate surface and sidewalls of the trenches 105 and 106 formedbetween the STI regions. Region 145 and 146 may be described asepitaxially regions that are separately epitaxially grown of a firsttype of epitaxial material (e.g., p- or n-type) on substrate surface 103at a bottom of trenches 105 and 106 formed beside (e.g., to the left andright of) shallow trench isolation (STI) region 108.

FIG. 10 shows material 140 polished or planarized to height H1 abovesurface 103. The top surface of material 140 may be polished to form aflat surface having a (100) crystal index above or at a height H1 of topsurface 156 of material 140 such as described for polishing material 142for FIG. 4. Top surface 156 may have the same height as and be planarwith top surfaces 116 or 118. In some cases, after or as a result ofpolishing, material 140 in trench 106 may be described as epitaxialregion 1046.

Polishing or planarizing epitaxial material 140 may be performed bychemical, physical or mechanical polishing as known in the art to form atop planar surface 156 of material 140. Epitaxial region 146 may have W1and L1, and H1. In some cases, materials 122, 130 and polished 140 maybe described as an “epitaxial region”; or a “stack” of epitaxial layersor materials (e.g., after polishing to height H1) similar to embodimentsof materials 122, 132 and 142 in region 145, respectively.

In some cases polished material 140 has height H1-H3. According to someembodiments, the difference in height between the top of material 130and the top of polished material 140 may be 50, 100, or 200 nanometers(nm).

FIG. 10 also shows epitaxial region 945 after removing mask 960 toexpose top surface 155. Mask 960 may be etched by a dry etching processthat removes the vertical thickness of Mask 960 as described forremoving mask 860. In some cases, mask 960 is removed by or duringpolishing above of material 140 to height H1.

FIG. 11 shows the semiconductor substrate of FIG. 1 after patterningepitaxial material formed in the trenches, and after etching the STIregions to form electronic device fins from a height of the fin layers(e.g., material 142 and 140) extending above etched top surfaces of theSTI regions. FIG. 11 shows pattern or masks 1160 and 1162 formed on topsurfaces 155 and 165 of epitaxial regions 945 and 1046. In some cases,masks 1160 and 1162 have width W1 and a height above surfaces 155 and156. The mask may have a length L1. In some cases, the masks are formedby or of photoresist alone, or a photoresist/oxide combination; or aphotoresist/nitride combination.

Masks 160 and 162 may have inner sidewalls 166 and 168 above or adjacentto sidewalls 115 and 112. In some cases, inner sidewalls 166 and 168 maybe planar surfaces parallel to and aligned with (e.g., directly above)planar sidewalls 112 and 114. Masks 160 and 162 may also have innersidewalls 170 and 172 above surfaces 113 and 114. Sidewalls 170 and 172may be planar surfaces parallel to and above planar sidewalls 113 and114, such as described for sidewalls 160 and 162 with respect tosidewalls 112 and 115.

According to embodiments, materials 142 and 140 may be patterned (e.g.,protected by masks 1160 and 1162), and STI regions 107, 108 and 110 maybe etched to form electronic device fins 1145 and 1146 from height HF ofthe fin layer extending above etched top surfaces 216, 217 and 218 ofthe STI regions. In some cases, top surfaces 155 and 165 of fin ordevice materials 142 and 140 are patterned with masks 1160 and 1162, andthen top surfaces 116, 117 and 118 are etched to remove thickness (e.g.,height HF) of STI regions 108, 107 and 110, to form electronic devicefins having height HF of the fin layers extending above the etched topsurfaces 216. Fins 1145 and 1146 may each be or include an “exposed”device well or gate layer extending or disposed height HF above theetched STI regions.

Fin 1145 may be an epitaxially grown layer or fin a first epitaxialmaterial (e.g., to become a P- or N-type material) having verticalsidewalls 266 and 270 extending height HF above the etched STI surfaces.Sidewalls 266 and 270 may be planar surfaces parallel to and alignedwith (e.g., directly below) planar sidewalls 166 and 170. In some cases,sidewalls 266 and 270 may be planar surfaces parallel to and aboveplanar sidewalls 113 and 115.

Fin 1146 may be an epitaxially grown layer or fin a different, secondepitaxial material (e.g., to become a N- or P-type material) havingvertical sidewalls 267 and 271 extending height HF above the etched STIsurfaces. Sidewalls 267 and 271 may be planar surfaces parallel to andaligned with (e.g., directly below) planar sidewalk 168 and 172. In somecases, sidewalls 267 and 271 may be planar surfaces parallel to andabove planar sidewalls 112 and 114.

In some cases, STI regions 107, 108 and 110 are selectively etched withrespect to masks 1160 and 1162 to form fins 1145 and 1146. The STIregions may be etched by wet or dry etching to remove material 104 thatis not protected by or below the masks. Etching the STI regions mayinclude descriptions above for etching material 104 to form STI regions107 and 108. In some cases, the STI regions may be etched using a wetetch (e.g., of HF) or a dry etch to remove only or not more than heightHF of the material of the STI regions. In some cases, STI regions 107,108 and 110 are simultaneously etched, such as during processing thatsimultaneously effects, is applied to, or removes material of those STIregions.

Each of fins 1145 and 1146 may have width W1, height HF above the STIregions, and length L1. In some cases the width W1, height HF and lengthL1 of the fins are equal to width W1, height H1-H3, and length L1 ofregion 145.

In some cases, fins 1145 and 1146 may be defined by exposed the topsurfaces 155 and 156 (after removal of masks 1160 and 1162); andsidewalls of fins 1145 and 1146.

According to embodiments, the height, length, width and surfaces of topsurfaces and sidewalls of fins 1145 and 1146 may be similar to thosedescribed for fins 145.

FIG. 12 shows the semiconductor substrate of FIG. 1 after formingconformal thicknesses of conformal epitaxial “cladding” materials grownfrom sidewall surfaces and a top surface of the electronic device fins.FIG. 12 shows fins 1145 and 1164 of FIG. 11 after removing masks 1160and 1162 to expose top surfaces 155 and 156.

The masks may be etched by a process similar to that described forremoving mask 160. In some cases, the etch may be a subtractive etch,such as to etch away the masks, with the exception of other materials,such as the STI material and the epitaxial materials (e.g., materials142 and 140. In some cases, the masks are selectively etched using a wetetch (e.g., of HF) or a dry etch to remove all of the masks.

After removing the masks, FIG. 12 shows fin 1146 after growing conformalthickness T1 of conformal epitaxial “cladding” 521 of expitaxialmaterial 522 from sidewall surfaces 267 and 271, and from top surface156 of material 140 of the electronic device fin 1146. In someembodiments, material 522 is formed or grown as a “cladding” layer ormaterial grown from sidewall surfaces 267 and 271 to form sidewallsurfaces 566 and 570, and from top surface 555, similar to descriptionsof FIG. 5 for forming sidewall surfaces 566 and 570; and grown from topsurface 155 to form top surface 555. Material 522 (e.g., Sidewallsurfaces 566 and 570) may not grow from, but may touch surfaces 216 and218.

In some cases, a “cladding” material (e.g., material 522) may be“selectively” grown only from a desired single crystal material (e.g,material 140 in this case) but not from other materials similar todescriptions of FIG. 5. According to some embodiments, material 522 maybe formed by epitaxial growth (e.g., heteroepitaxy growth) similar todescriptions of FIG. 5. Material 522 may be formed on or touchingmaterial 140, to a conformal thickness (e.g., a thickness increasing the“height” on the top surface and “width” on the sidewalls) over fin 1146,similar to descriptions of FIG. 5.

FIG. 12 shows fin 1146 after epitaxially growing conformal thickness T2of conformal epitaxial “cladding” 621 of expitaxial material 622 fromsidewall surfaces 566 and 570, and from top surface 555 of material 522over electronic device fin 1146. In some embodiments. material 622 isformed or grown from material 522 as described for FIG. 6. Material 622(e.g., sidewall surfaces 666 and 670) may not grow from, but may touchsurfaces 216 and 218. In some cases, material 622 may be defined byexposed the top surface 655; sidewalls 666 and 670 of the epitaxialregions. In some cases, sidewalls 666 and 670 may be planar surfacesparallel to and aligned with (e.g., directly adjacent to and wider thanby thickness T2) planar sidewalls 566 and 570. FIG. 12 shows fin 1146after epitaxially growing conformal thickness T3 of conformal epitaxial“cladding” 631 of expitaxial material 632 from sidewall surfaces 566 and570, and from top surface 555 of material 522 over electronic device fin1146.

In some embodiments, material 632 is formed or grown from material 522as described for FIG. 6. Material 662 (e.g., sidewall surfaces 676 and680) may not grow from, but may touch surfaces 216 and 218. In somecases, material 632 may be defined by exposed the top surface 655;sidewalls 666 and 670 of the epitaxial regions. In some cases, sidewalls676 and 680 may be planar surfaces parallel to and aligned with (e.g.,directly adjacent to and wider than by thickness T3) planar sidewalls566 and 570.

After removing the masks, FIG. 12 shows fin 1145 after growing conformalthickness T4 of conformal epitaxial “cladding” 1221 of expitaxialmaterial 1222 from sidewall surfaces 266 and 270, and from top surface155 of material 142 of the electronic device fin 1145. In someembodiments, material 1222 is formed or grown as a “cladding” layer ormaterial grown from material 142, similar to descriptions of FIG. 5 forgrowing material 522 from a total length or from portions of the lengthof material 142. In some embodiments, material 1222 is formed or grownas a “cladding” layer or material grown from sidewall surfaces 266 and270 to form sidewall surfaces 1266 and 1270, and from top surface 1255,similar to descriptions of FIG. 5 for forming sidewall surfaces 566 and570; and grown from top surface 155 to form top surface 555. Material1222 (e.g., Sidewall surfaces 1266 and 1270) may not grow from, but maytouch surfaces 216 and 217.

In some cases, a “cladding” material (e.g., material 1222) may be“selectively” grown only from a desired single crystal material (e.g,material 142 in this case) but not from other materials similar todescriptions of FIG. 5. According to some embodiments, material 1222 maybe formed by epitaxial growth (e.g., heteroepitaxy growth) similar todescriptions of FIG. 5. Material 1222 may be formed on or touchingmaterial 142, to a conformal thickness (e.g., a thickness increasing the“height” on the top surface and “width” on the sidewalls) over fin 1145,similar to descriptions of FIG. 5.

FIG. 12 shows fin 1145 after epitaxially growing conformal thickness T5of conformal epitaxial “cladding” 1231 of expitaxial material 1232 fromsidewall surfaces 1266 and 1270, and from top surface 1255 of material1222 over electronic device fin 1145. In some embodiments, material 1232is formed or grown as a “cladding” layer or material grown from material522, similar to descriptions of FIG. 6 for growing material 622 from atotal length or from portions of the length of material 522. Material1232 (e.g., sidewall surfaces 1266 and 1270) may not grow from, but maytouch surfaces 216 and 217. In some cases, material 1322 may be definedby exposed the top surface 1265; sidewalls 1267 and 1271 of theepitaxial regions. In some cases, sidewalls 1267 and 1271 may be planarsurfaces parallel to and aligned with (e.g., directly adjacent to andwider than by thickness T5) planar sidewalls 1266 and 1270.

It can be appreciated that the descriptions above (e.g., with respect toFIGS. 7-12) can also be applied to first form mask 860 on trench 105 andform fin 1146 in trench 106; and then form mask 960 over trench 106 (andfin 1146) and form fin 1145 in trench 105.

According to a seventh set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trenches 105 and 106, but not from STI material or surfacesforming the trenches. In these cases, in trench 105, materials 122, 132,522, and 622 are similar to the descriptions above for the fifth set ofembodiments. In these cases, in trench 106, materials 122, 132,522, 622and 632 are similar to the descriptions above for the sixth set ofembodiments.

According to a ninth set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trenches 105 and 106, but not from STI material or surfacesforming the trenches. In these cases, in trench 105, materials 122, 132,522, and 622 are similar to the descriptions above for the fifth set ofembodiments. In these cases, in trench 106, materials 122, 132, 522, 622and 632 are similar to the descriptions above for the fourth set ofembodiments.

According to another set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is aselectively grown epitaxial layer that is grown from portions of surface103 in trenches 105 and 106, but not from STI material or surfacesforming the trenches. In these cases, in trench 105, materials 122, 132,522, and 622 are similar to the descriptions above for any of the firstthrough sixth sets of embodiments. In these cases, in trench 106,materials 122, 132, 522, 622 and 632 are similar to the descriptionsabove for any of the first through sixth sets of embodiments.

FIG. 13 is a schematic cross section view of a portion of asemiconductor substrate base after forming a layer of epitaxial materialon a top surface of the substrate, and a layer of STI material on a topsurface of the epitaxial material. FIG. 13 shows semiconductor substrateor base 101 of material 102 having top surface 103.

FIG. 13 shows a first layer of material 122 epitaxially grown fromsurface 103 as a blanket layer. Material 122 may be epitaxially grownfrom the crystal surface of substrate surface 103 along all of surface103, such as described above for growing material 122 in trench 105 forFIG. 3. with the difference being that material 122 is not grown withrespect to STI material surfaces 113, 115, 117 and 116. Material 122 maybe epitaxially grown prior to forming STI material 104. Material 122 maybe grown to height H2. In some cases, material 122 is planarized orpolished to height H2 and has a planar top surface.

FIG. 13 also shows a layer of shallow trench isolation (STI) material104 formed or grown on top surface 1403 of material 122, such asdescribed above for growing material 104 on surface 103 for FIG. 1, withthe difference being that material 104 is grown from material 122.Material 104 may be grown to height H1. In some cases, material 122 isplanarized or polished to height H1 and has a planar top surface.

In some cases, the bottom surface of material 104 may have the same(100) crystal orientation as that of top surface 1403 of material 122.In some cases, the bottom surface of material 104 may have the samecrystal lattice size as that of top surface 1403 of material 122.Material 104 may be a relaxed material (e.g., have anon-strainedlattice) with respect to its interface (e.g., where it is chemically oratomically bonded to the surface below) with top surface 1403 ofmaterial 122.

FIG. 14 shows the semiconductor substrate of FIG. 13 after formingtrenches between the STI regions. FIG. 14 shows trenches 1405 and 1406defined between STI regions 1407, 1408 and 1410 and top surface 1403.These regions and trenches may be formed as described above for formingregions 107, 108 and trench 105, except that material 104 is etched downto surface 1403 of material 122. Such etching may include etching asdescribed for etching material 104 for FIG. 7, but may be selective withrespect to (e.g., extend only to) top surface 1403. Trenches 1405 and1406 may be adjacent trenches that are next to each other without otherdevice fins formed in or within region 108 between trenches 105 and 106.

More specifically, STI region 1407 has sidewall 1413 and top surface117. STI region 1408 has sidewalls 1412 and 1415, and has top surface116. STI region 1410 has sidewall 1414 and top surface 118. Sidewalls1412, 1413, 1414 and 1415 may be vertical planar surfaces perpendicularto (e.g., at a right angle with respect to) horizontal planar surfacessurface 103 and horizontal planar surfaces 116, 117 and 118. Thesidewalls may comprise or be STI material 104. STI regions 1407, 1408and 1410 may have a width W1 defined by the horizontal distance betweentheir sidewalls. STI regions 1407, 1408 and 1410 may have height H1-H2defined by the vertical distance between top surface 1403 and topsurface 116, 117 and 118, respectively. STI regions 1407, 1408 and 1410may have a length L1.

Trenches 1405 and 1406 may be defined by the sidewalls of regions 1407.1408 and 1410; and surface 1403. Trenches 1405 and 1406 may includesurface 1403 of material 122 exposed at the bottom of the trench, suchas a planar or planarized surface of crystal material. In some cases,each of trenches 1405 and 1406 is defined by additional sidewalls ofother STI regions, such as a front and back STI having sidewall similarto sidewalls 1412, 1413, 1414 and 1415, and top surfaces defining lengthL1 of trenches 1405 and 1406. Trench 1405 and 1406 may have width W1defined by the horizontal distance between their sidewalls. Trenches1405 and 1406 may have height H1-H2. Trenches 1405 and 1406 may have alength L1.

FIG. 14 shows trenches 1405 and 1406. However it is contemplated thatmore, similar trenches and STI regions may exist on substrate 101 (e.g.,such as at least hundreds or hundreds of thousands).

FIG. 15 shows the semiconductor substrate of FIG. 13 after forming amask over material 122 in trench 1406, and forming second epitaxialmaterial 142 in the trench 1405. FIG. 15 shows pattern or mask 860formed on top surfaces of material 122 in trench 1406, sidewall surfacesof trench 1406, and at least a portion of top surfaces 116 and 118.

Forming mask 860 on top surfaces of material 122 in trench 1406,sidewall surfaces of trench 1406, and at least a portion of top surfaces116 and 118 for FIG. 15 may be similar to the description for formingmask 860 on top surfaces of material 122 in trench 106, sidewallsurfaces of trench 106, and at least a portion of top surfaces 116 and118 for FIG. 8. Mask 860 may seal off trench 1406 so that after formingmask 860, material grown or deposited in trench 1405 does not entertrench 1406.

FIG. 15 shows a second layer of material 142 epitaxially grown from atop surface of material 122. Material 142 may be grown to height H3above surface 1403. Material 142 may be epitaxially grown from thecrystal top surface of material 122. Material 142 may be formed byepitaxial growth (e.g., heteroepitaxy) from material 122, similar todescriptions above for growing material 132 from material 122 for FIG.3. Material 142 may be epitaxially grown from the crystal surface ofmaterial 122 in trench 1406 with respect to STI material surfaces 1413,1415, 116 and 117, similar to the description above for FIG. 8 andgrowing material 142 in trench 105 with respect to STI material surfaces113, 115, 117 and 118, respectively.

FIG. 16 shows the semiconductor substrate of FIG. 13 after polishing andpatterning epitaxial material 142 formed in trench 1405, removing mask860, forming mask 960, and forming a second epitaxial material in trench1406. In some embodiments, material 142 may be polished or planarized,mask 860 may be removed, and mask 960 may be formed for FIG. 16 similarto the description for FIG. 9.

In some cases, after or as a result of polishing, material 142 in trench1405 may be described as epitaxial region 1645. Mask 960 may seal offtrench 1405 and material 142 so that after forming mask 960, materialgrown or deposited in trench 1406 does not enter trench 1405 or touchmaterial 142.

FIG. 16 shows a second layer of material 140 epitaxially grown from atop surface of material 122. Material 140 may be grown to height greaterthan H1 above surface 103. In some cases material 142 have height H1-H3.Material 140 may be formed by epitaxial growth (e.g., heteroepitaxy)from material 122, similar to descriptions above for growing material142 from material 122 for FIG. 9. Material 140 may be epitaxially grownfrom the crystal surface of material 122 in trench 1206 with respect toSTI material surfaces 1212, 1214, 116 and 118, similar to thedescription above for FIG. 9 and growing material 142 in trench 105 withrespect to STI material surfaces 113, 115, 117 and 116, respectively.

Material 140 may be a “device” layer, such as a layer on or in whichcircuity devices are formed, as known in the art, such as described formaterial 142. Such devices may include devices described herein.

FIG. 17 shows the semiconductor substrate of FIG. 13 after polishingepitaxial material 140 and removing mask 960 to form epitaxial region1746. Regions 1645 and 1746 may be epitaxially grown regions of a firstepitaxial material (e.g., to become a P- or N-type material) on thesubstrate surface and sidewalls of the trenches 1405 and 1406 formedbetween the STI regions. Regions 1745 and 1846 may be described asepitaxially regions that are separately epitaxially grown of a firsttype of epitaxial material (e.g., p- or n-type) on substrate surface 103at a bottom of trenches 1405 and 1406 formed beside (e.g., to the leftand right of) shallow trench isolation (STI) region 1408.

FIG. 17 shows material 140 polished or planarized to height H1 abovesurface 103. The top surface of material 140 may be polished to form aflat surface having a (100) crystal index above or at a height H1 of topsurface 156 of material 140 such as described for polishing material 142for FIG. 4. Top surface 156 may have the same height as and be planarwith top surfaces 116 or 118. In some cases, after or as a result ofpolishing, material 140 in trench 106 may be described as epitaxialregion 1846.

Polishing or planarizing epitaxial material 140 may be performed bychemical, physical or mechanical polishing as known in the art to form atop planar surface 156 of material 140. Epitaxial region 1846 may haveW1 and L1, and H1. In some cases, materials 122 and polished 140 may bedescribed as an “epitaxial region”; or a “stack” of epitaxial layers ormaterials (e.g., after polishing to height H1) similar to embodiments ofmaterials 122, 132 and 142 in region 145, respectively. In sonic casespolished material 140 has height H1-H3. According to some embodiments,the difference in height between the top of material 122 and the top ofpolished material 140 may be 100, 200, or 300 nanometers (nm).

FIG. 17 also shows epitaxial region 1745 after removing mask 960 toexpose top surface 155. Mask 960 may be etched by a dry etching processthat removes the vertical thickness of Mask 960 as described forremoving mask 860. In some cases, mask 960 is removed by or duringpolishing above of material 140 to height H1.

FIG. 18 shows the semiconductor substrate of FIG. 13 after patterningepitaxial material formed in the trenches, and after etching the STIregions to form electronic device fins from a height of the fin layers(e.g., material 142 and 140) extending above etched top surfaces of theSTI regions. FIG. 18 shows pattern or masks 1160 and 1162 formed on topsurfaces 155 and 165 of epitaxial regions 1645 and 1746 similar toforming masks 1160 and 1162 formed on top surfaces 155 and 165 ofepitaxial regions 945 and 1046 of FIG. 11.

According to embodiments, materials 142 and 140 may be patterned (e.g.,protected by masks 1160 and 1162), and STI regions 1407, 1408 and 1410may be etched to form electronic device fins 1845 and 1846 from heightHF of the fin layer extending above etched top surfaces 216, 217 and 218of the etched STI regions. In some cases, this may be performed similarto the FIG. 11 description for patterning top surfaces 155 and 165 offin or device materials 142 and 140 with masks 1160 and 1162, and thenetching top surfaces 116, 117 and 118 to remove thickness (e.g., heightHF) of STI regions 108, 107 and 110, to form electronic device finshaving height HF of the fin layers extending above the etched topsurfaces 216. Fins 1845 and 1846 may each be or include an “exposed”device well or gate layer extending or disposed height HF above theetched STI regions.

Fin 1845 may be an epitaxially grown layer or fin a first epitaxialmaterial (e.g., to become a P- or N-type material) having verticalsidewalls 266 and 270 extending height HF above the etched STI surfaces.Fin 1846 may be an epitaxially grown layer or fin a different, secondepitaxial material (e.g., to become a N- or P-type material) havingvertical sidewalls 267 and 271 extending height HF above the etched STIsurfaces.

Each of fins 1845 and 1846 may have width W1, height HF above the STIregions, and length L1. In some cases the width W1, height HF and lengthL1 of the fins are equal to width W1, height H1-H3, and length L1 ofregion 1645. In some cases, fins 1845 and 1846 may be defined by exposedthe top surfaces 155 and 156 (after removal of masks 1160 and 1162); andsidewalls of fins 1845 and 1846. According to embodiments, the height,length, width and surfaces of top surfaces and sidewalls of fins 1845and 1846 may be similar to those described for fins 1145 and 1146.

FIG. 19 shows the semiconductor substrate of FIG. 13 after formingconformal thicknesses of conformal epitaxial “cladding” materials grownfrom sidewall surfaces and a top surface of the electronic device fins.FIG. 19 shows fins 1845 and 1864 of FIG. 18 after removing masks 1160and 1162 to expose top surfaces 155 and 156. The masks may be etched bya process similar to that described for removing the masks in FIG. 12.

After removing the masks, FIG. 19 shows fin 1846 after growing conformalthickness T1 of conformal epitaxial “cladding” of expitaxial material522 from sidewall surfaces 267 and 271, and from top surface 156 ofmaterial 140 of the electronic device fin 1846. In some embodiments,material 522 is formed or grown as a “cladding” layer or material grownfrom sidewall surface and from top surface of material 140, similar todescriptions of FIG. 12.

FIG. 19 shows fin 1846 after epitaxially growing conformal thickness T2of conformal epitaxial “cladding” 621 of expitaxial material 622 fromsidewall surfaces 566 and 570, and from top surface 555 of material 522over electronic device fin 1846. In some embodiments, material 622 isformed or grown from material 522 as described for FIG. 12.

FIG. 19 shows fin 1846 after epitaxially growing conformal thickness T3of conformal epitaxial “cladding” 631 of expitaxial material 632 fromsidewall surfaces 566 and 570, and from top surface 555 of material 522over electronic device fin 1846. In some embodiments, material 632 isformed or grown from material 522 as described for FIG. 12.

After removing the masks. FIG. 19 shows fin 1145 after growing conformalthickness T4 of conformal epitaxial “cladding” 1221 of expitaxialmaterial 1222 from sidewall surfaces 266 and 270, and from top surface155 of material 142 of the electronic device fin 1145. In someembodiments, material 1222 is formed or grown from material 142 asdescribed for FIG. 12.

FIG. 19 shows fin 1845 after epitaxially growing conformal thickness T5of conformal epitaxial “cladding” 1231 of expitaxial material 1232 fromsidewall surfaces 1266 and 1270, and from top surface 1255 of material1222 over electronic device fin 1845. In some embodiments, material 1232is formed or grown from material 1222 as described for FIG. 12.

In some cases, According to embodiments, the height, length, width andsurfaces of top surfaces and sidewalls of materials 522, 622, 632, 1222and 1232 in FIG. 19 may be similar to those described for FIG. 12. Itcan be appreciated that the descriptions above (e.g., with respect toFIGS. 13-19) can also be applied to first form mask 860 on trench 1405and form fin 1846 in trench 1406; and then form mask 960 over trench1406 (and fin 1846) and form fin 1845 in trench 1405.

According to an eighth set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is ablanket (e.g., non-selective) epitaxial layer grown from all of surface103 below STI material and two different trenches, prior to forming theSTI material of the trenches.

In these cases, in trench 1405, materials 122 (but as a blanket layer atnoted above), 142 (e.g., material 132/142), 1222, and 1232 are similarto the descriptions above for the seventh set of embodiments. In thesecases, in trench 1406, material 122 (but as a blanket layer at notedabove) is similar to the descriptions above for the seventh set ofembodiments.

In these cases, material 132 and 142 are the same material (e.g.,material 132/142). In these cases, material 132/142 is a buffer materialupon which a device material or layer is clad (e.g., as channel material522). In these cases, material 142 may extend below surfaces 216 and217, such as where H3 is less than shown in the figures and HF extendsbelow surfaces 216 and 217. In these cases, layer 142 is a device bufferlayer of either (1) a layer of InP material (e.g., 50 percent In, and 50percent P), or (2) a layer of InAlAs material (e.g., 50 percent In, 25percent Al and 25 percent As) such as for an N-type channel formed ofmaterial 522 clad on fin 245. In some cases the layer of InAlAs is 70percent InAs and 30 percent AlAs; or In_(x)Al_(1-x)As where x=0.7; or70% of In and 30% of Al for group III side and 100% for As which isgroup V material.

In such cases, material 522 is a channel material or layer, such as fora tri-gate device having the channel conducting chares along thesidewall and top material of material 522; material 622 is agate regionor layer (e.g., gate dielectric and gate electrode), such as for atri-gate device having the gate biasing the conducted charges along thesidewall and top material of material 522; and material 632 includesjunction regions or layers on or touching material 522, such as for atri-gate device having separate source and drain region at or acrossdifferent portions of length L1 along the sidewall and top material ofmaterial 522.

In these cases, material 522 is a cladding layer of doped N-type InGaAschannel material (e.g., 70 percent InAs and 30 percent GaAs; or 70% ofIn and 30% of Ga for group III side and 100% for As which is group Vmaterial; or In_(x)Al_(1-x)As where x=0.53). In these cases, material622 is gate delectric or electrode of InP cladding material (e.g., 50percent In, and 50 percent P) on or over an N-type channel formed ofmaterial 522 clad on fin 245. In these cases, material 632 representstwo junction regions of InGaAs material (e.g., 70 percent InAs and 30percent GaAs; or 70% of In and 30% of Ga for group III side and 100% forAs which is group V material; or In_(x)Al_(1-x)As where x=0.53) ascladding material grown from channel material 142.

According to another set of exemplary embodiments, material 122 is asingle layer of a “buffer” material having a lattice constant betweenthat of surface 103 and material 132. In these cases, layer 122 is ablanket (e.g., non-selective) epitaxial layer grown from all of surface103 below STI material and two different trenches, prior to forming theSTI material of the trenches.

In these cases, in trench 1405, materials 122 (but as a blanket layer atnoted above), 132, 142, 1222, and 1232 are similar to the descriptionsabove for any of the first through sixth sets of embodiments. In thesecases, in trench 1406, material 122 (but as a blanket layer at notedabove), 132, 522, 622 and 632 are similar to the descriptions above forany of the first through sixth sets of embodiments.

FIG. 20 is an example process 2000 for epitaxially cladding a firstconformal thickness of a first conformal epitaxial material on sidewallsurfaces and a top surface of a single crystal electronic device finafter the fin is (1) epitaxially grown from a substrate surface at abottom of a trench formed between STI regions, and (2) patterned whilethe STI regions are etched to form a height of the fin layer extendingabove etched top surfaces of the STI regions. FIG. 20 shows process 2000beginning with block 2004 where a fin layer of a fin epitaxial materialis epitaxially grown from a bottom of a trench formed between shallowtrench isolation (STI) sidewalls of STI regions. The fin epitaxialmaterial may include a first, second and third layer of epitaxialmaterials epitaxially grown on a substrate surface at a bottom of one ortwo trenches, each formed by a plurality of shallow trench isolation(STI) regions. The STI regions may have STI sidewalls defining a firstwidth W1 and a first height HI of the trenches. The first height 111 maybe at least 1.5 times the first width W1. The substrate surface may besilicon and have a (100) crystal orientation index. This may includeforming a fin material in one or more of trenches 105, 106, 1405 and/or1406 as described herein. Block 2004 may include descriptions herein forforming regions 145, 945, 1046, 1645, and/or 1746 as described herein.

In some optional cases, prior to growing the fin layer, a blanket bufferlayer of a blanket buffer epitaxial material is epitaxially grown from asubstrate surface; a top surface of the blanket layer forming a bottomof first and second trenches. Here, the first and second fin layers aregrown in the first and second trenches from the top surface of theblanket layer. This may include forming a fin in one or more of trenches1405 and/or 1406 as described herein. This may include descriptionsherein for forming regions 1645, and/or 1746 as described herein

In some optional cases, prior to growing the fin layer, a STI layer(formed on the substrate or on the optional blanket epitaxial layer) isetched to form the one or two trenches between the STI sidewalls. Thismay include forming a fin in one or more of trenches 105 and 106; or1405 and 1406 as described herein. This may include forming regions 945and 1046; or 1645 and 1746 as described herein

At block 2006, a top surface of the fin layer is patterned and theplurality of STI regions are etched to form an electronic device finfrom a height of the fin layer extending above etched top surfaces ofthe plurality of STI regions. This may include forming a fin in one ormore of trenches 105, 106, 1405 and/or 1406 as described herein. Block2006 may include descriptions herein for forming fins 245, 1145, 1146,1845, and/or 1846 as described herein.

At block 2008, a first conformal thickness of a first conformalepitaxial material is epitaxially clad on sidewall surfaces and a topsurface of the electronic device fin. This may include forming claddingmaterial 522, 632, 1222, and/or 1232 as described herein.

At block 2010, in some optional cases, a second conformal thickness of adifferent second conformal epitaxial material is epitaxially clad onsidewall surfaces and a top surface of the first conformal thickness.This may include forming cladding material 622, 632, 1222, and/or 1232as described herein.

At block 2012, in some optional cases, a third conformal thickness of adifferent third conformal epitaxial material is epitaxially clad onsidewall surfaces and a top surface of the first conformal thickness orof the fin material. This may include forming cladding material 632 asdescribed herein.

At block 2014, in some optional cases, another fin layer of another finepitaxial material is epitaxially grown from a bottom of a second trenchformed between shallow trench isolation (STI) sidewalls of STI regions.This may include the descriptions for block 2004 but apply to growing afin material in a second trench, adjacent to the first trench, asdescribed herein. This may include forming a fin in one or more oftrenches 106 and/or 1406 as described herein. Block 2014 may includedescriptions herein for forming fins 1146 and/or 1846 as describedherein.

At block 2016, in some optional cases, a top surface of the other finlayer is patterned and the plurality of STI regions are etched to formanother electronic device fin from a height of the fin layer extendingabove etched top surfaces of the plurality of STI regions. This mayinclude the descriptions for block 2006 but apply to forming a fin in asecond trench, adjacent to the first trench, as described herein. Thismay include forming a fin in one or more of trenches 106 and/or 1406 asdescribed herein. Block 2016 may include descriptions herein for formingfins 1146 and/or 1846 as described herein.

At block 2018, in some optional cases, another conformal thickness ofanother conformal epitaxial material is epitaxially clad on sidewallsurfaces and a top surface of the other electronic device fin. This mayinclude the descriptions for block 2008 but apply to forming anotherconformal epitaxial material on another fin in a second trench, adjacentto the first trench, as described herein. This may include formingcladding material 522, 632, 1222, and/or 1232 on another fin in a secondtrench, adjacent to the first trench, as described herein.

Thus, embodiments have been described herein to provide a more efficientand reliable process for forming both p- and n-type epitaxial electronicdevice fins from the same substrate by integrating VLSI-compatible finstructures with selective epitaxial growth and fabricating devicesthereon. Such integration may include forming or growing different typesof P- and N-type material in different, adjacent epitaxial regions grownfrom the same substrate; and then forming a pair of electronic devicefins of the different type material in each of the different epitaxialregions. Thus, the embodiments described herein provide benefits andadvantages as compared to other processes and devices, including (1)co-integration of n- and p-mos electronic device fins from epitaxialregions grown from or on the same silicon surface 103 for CMOSimplementation (e.g., and within certain length L, width W, and height Hrequirements as noted herein). Such co-integration of n- and p-mos mayinclude forming of n- and p-mos fins 245, 1145, 1146, 1845, and/or 1846from the same silicon surface 103 (or 1403) in one or more of trenches105, 106, 1405 and/or 1406 as described herein. Such co-integration ofn- and p-mos may include forming of n- and p-mos regions 145, 945, 1046,1645, and/or 1746 from the same silicon surface 103 (or 1403) in one ormore of trenches 105, 106, 1405 and/or 1406 for both n and p-mos devicesprior to etching both n- and p-mos electronic device fins from thoseregions.

Some embodiments described herein also provide benefits and advantagesas compared to other processes and devices, including (2) a largereduction of defects propagating to the device layers on either or bothn- and p-side electronic device fins. In some embodiments, since thedefects (e.g., crystaline defects) in trenches 105, 106, 1405 and/or1406 have not extended into or do not exist in the device material 142(when material 142 is a channel material), 522, 622, 632, 1222, and/or1232, the fins (e.g., device material sidewalls and top surfaces) mayprovide electronic device material (e.g., wells and channels, etc.) inwhich defect free fin based devices may be formed (e.g., tri-gatedevices). For example, by forming electronic device fins (or portions)as described herein, it is possible to avoid or minimize crystalinedefects that result in the fins due to or from a large lattice mismatchin materials when certain materials (e.g., type III-V, or type IV (e.g.,Ge) materials) are epitaxially grown on a Silicon material substrate, intrenches. Such defects include those trapped or along the sidewall ofthe STI forming the trenches. By avoiding or minimizing these crystalinedefects can lead to yield and variation issues in a device built on adevice layer or device sidewall of the fins.

Some embodiments described herein also provide benefits and advantagesas compared to other processes and devices, including (3) a largereduction of defects propagating to high K gate layer dielectricmaterial formed on either or both n- and p-side electronic device fins.In some embodiments, since the defects (e.g., crystaline defects) intrenches 105, 106, 1405 and/or 1406 have not extended into or do notexist in the device material 142 (when material 142 is a channelmaterial), 522, 622, 632, 1222, and/or 1232, the high K gate layerdielectric material formed form any of these materials may have reducedbroken bonds and/or extra charges, thus providing improved electronicgate dielectric material for fin based devices (e.g., tri-gate devices).

FIG. 21 illustrates a computing device 2100 in accordance with oneimplementation. The computing device 2100 houses board 2102. Board 2102may include a number of components, including but not limited toprocessor 2104 and at least one communication chip 2106. Processor 2104is physically and electrically connected to board 2102. In someimplementations at least one communication chip 2106 is also physicallyand electrically connected to board 2102. In further implementations,communication chip 2106 is part of processor 2104.

Depending on its applications, computing device 2100 may include othercomponents that may or may not be physically and electrically connectedto board 2102. These other components include, but are not limited to,volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flashmemory, a graphics processor, a digital signal processor, a cryptoprocessor, a chipset, an antenna. a display, a touchscreen display, atouchscreen controller, a battery, an audio codec, a video codec, apower amplifier, a global positioning system (GPS) device, a compass, anaccelerometer, a gyroscope, a speaker, a camera, and a mass storagedevice (such as hard disk drive, compact disk (CD), digital versatiledisk (DVD), and so forth).

Communication chip 2106 enables wireless communications for the transferof data to and from computing device 2100. The term “wireless” and itsderivatives may be used to describe circuits, devices, systems, methods,techniques, communications channels, etc., that may communicate datathrough the use of modulated electromagnetic radiation through anon-solid medium. The term does not imply that the associated devices donot contain any wires, although in some embodiments they might not.Communication chip 2106 may implement any of a number of wirelessstandards or protocols, including but not limited to Wi-Fi (IEEE 802.11family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution(LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT,Bluetooth, derivatives thereof, as well as any other wireless protocolsthat are designated as 3G, 4G, 5G, and beyond. Computing device 2100 mayinclude a plurality of communication chips 2106. For instance, a firstcommunication chip 2106 may be dedicated to shorter range wirelesscommunications such as Wi-Fi and Bluetooth and a second communicationchip 2106 may be dedicated to longer range wireless communications suchas GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.

Processor 2104 of computing device 2100 includes an integrated circuitdie packaged within processor 2104. In some implementations, theintegrated circuit die includes epitaxially cladding a first conformalthickness of a first conformal epitaxial material on sidewall surfacesand a top surface of a single crystal electronic device fin after thefin is (1) epitaxially grown from a substrate surface at a bottom of atrench formed between STI regions, and (2) patterned while the STIregions are etched to form a height of the fin layer extending aboveetched top surfaces of the STI regions as described with reference toFIGS. 1-20. The term “processor” may refer to any device or portion of adevice that processes electronic data from registers and/or memory totransform that electronic data into other electronic data that may hestored in registers and/or memory.

Communication chip 2106 also includes an integrated circuit die packagedwithin communication chip 2106. In accordance with anotherimplementation. a package including a communication chip incorporatesone or more fin devices having cladding device layers such as describedabove. In further implementations, another component housed withincomputing device 2100 may contain a microelectronic package including afin device having cladding device layers such as described above.

In various implementations, computing device 2100 may be a laptop, anetbook, a notebook, an ultrabook, a smartphone, a tablet, a personaldigital assistant (PDA), an ultra mobile PC, a mobile phone, a desktopcomputer, a server, a printer, a scanner, a monitor, a set-top box, anentertainment control unit, a digital camera, a portable music player,or a digital video recorder. In further implementations, computingdevice 2100 may be any other electronic device that processes data.

EXAMPLES

The following examples pertain to embodiments.

Example 1 is a method to form an electronic device fin comprising:epitaxially growing a

On layer of a fin epitaxial material from a substrate surface at abottom of a trench formed between a plurality of shallow trenchisolation (STI) regions having STI sidewalls defining a first width anda first height of the trench; patterning a top surface of the fin layerand etching the plurality of STI regions to form an electronic devicefin from a height of the fin layer extending above etched top surfacesof the plurality of STI regions; and epitaxially cladding a firstconformal thickness of a first conformal epitaxial material on sidewallsurfaces and a top surface of the electronic device fin.

In Example 2, the subject matter of Example 1 can optionally includewherein epitaxially cladding includes growing the first conformalthickness of a single crystal conformal epitaxial material from thesidewall surfaces and from the top surface of the electronic device fin.

In Example 3, the subject matter of Example 1 can optionally includewherein epitaxially cladding includes growing the first conformalthickness of a single crystal conformal epitaxial material acrossportions of top surfaces of the plurality of STI regions; but notgrowing the first conformal thickness of the first conformal epitaxialmaterial from a polycrystaline material of the portions of top surfacesof the plurality of STI regions.

In Example 4, the subject matter of Example 1 can optionally includewherein the fin epitaxial material comprises a device channel material,and the first conformal epitaxial material comprises a gate buffermaterial formed over a portion of a total length of the channelmaterial.

In Example 5, the subject matter of Example 4 can optionally includewherein the first buffer epitaxial material comprises an ART epitaxialInP or SiGe material; the second buffer epitaxial material comprises anART epitaxial buffer InAlAs or SiGe material; the device channelmaterial comprises an InGaAs or Ge material; and the first conformalepitaxial material comprises an InP or Si material formed over a portionof a total length of the channel material.

In Example 6, the subject matter of Example 1 can optionally includewherein the fin IS material comprises a buffer material, and the firstconformal epitaxial material comprises a channel material formed overall of a total length of the channel material.

In Example 7, the subject matter of Example 6 can optionally includewherein the first buffer material comprises an epitaxial InP or SiGematerial; and the second buffer material comprises an epitaxial bufferInAlAs or SiGe material; and the first conformal epitaxial materialcomprises an InGaAs or Ge channel material formed over a total length ofthe channel material.

In Example 8, the subject matter of Example 1 can optionally includefurther comprising: epitaxially cladding a second conformal thickness ofa second conformal epitaxial material on sidewalls and a top surface ofthe first conformal thickness.

In Example 9, the subject matter of Example 8 can optionally includewherein the fin material comprises one of a buffer material and a devicechannel material; the first conformal epitaxial material comprises oneof a channel material and a gate buffer material; and the secondconformal epitaxial material comprises one of a device gate dielectricand a junction region material formed over the first conformal epitaxialmaterial.

In Example 10, the subject matter of Example 8 can optionally includefurther comprising: epitaxially cladding a third conformal thickness ofa third conformal epitaxial material on sidewalls and a top surface ofthe FIRST conformal thickness.

In Example 11, the subject matter of Example 10 can optionally includewherein the fin material comprises one of a buffer material and a devicechannel material; the first conformal epitaxial material comprises oneof a channel material and a gate buffer material; second conformalepitaxial material comprises a device gate dielectric; and the thirdconformal epitaxial material comprises a junction region material formedover the first conformal epitaxial material.

In Example 12, the subject matter of Example 1 can optionally includewherein the fin layer is a first fin layer, the fin epitaxial materialis a first fin epitaxial material, the trench is a first trench, theplurality of STI regions are a first plurality of STI regions havingfirst STI sidewalk, the top surface of the fin layer is a first topsurface, and further comprising: epitaxially growing a second fin layerof a second fin epitaxial material from the substrate surface at abottom of a second trench formed between a second plurality of STIregions having second STI sidewalls defining the first width and thefirst height of the second trench; patterning a second buffer topsurface of the second fin layer and etching the second plurality of STIregions to form a second electronic device fin from a height of thesecond fin layer extending above etched top surfaces of the secondplurality of STI regions; and epitaxially cladding a second conformalthickness of a second conformal epitaxial material on sidewalls and atop surface of the second electronic device fin.

In Example 13, the subject matter o Example 12 can optionally includewherein the first fin layer comprises a first buffer layer of a firstbuffer epitaxial material, and a second buffer layer of a second bufferepitaxial material grown from the first buffer epitaxial material in thefirst trench; wherein the second fin layer comprises the first bufferlayer of the first buffer epitaxial material, the second buffer layer ofthe second buffer epitaxial material grown from the first bufferepitaxial material, and a third buffer layer of a third buffer epitaxialmaterial grown from the second buffer epitaxial material in the secondtrench; wherein the first conformal epitaxial material comprises a firstchannel material formed over all of a total length of the second bufferlayer over the first trench; and wherein the fourth conformal epitaxialmaterial comprises a different, second channel material formed over allof a total length of the third buffer layer over the second trench.

In Example 14, the subject matter of Example 12 can optionally includefurther comprising: prior to growing the fin layer, epitaxially growinga blanket buffer layer of a blanket buffer epitaxial material from thesubstrate surface, a top surface of the blanket layer forming a bottomof the first and second trenches, wherein the first and second finlayers are grown in the first and second trenches from the top surfaceof the blanket layer; epitaxial growing a second buffer epitaxialmaterial from the top surface of the blanket buffer epitaxial materialin the first trench; and epitaxially growing a different, third bufferepitaxial material from the top surface of the blanket buffer epitaxialmaterial in the second trench.

Example 15 is an electronic device fin comprising: a fin layer of a finepitaxial material on a substrate surface at a bottom of a trench formedbetween a plurality shallow trench isolation (STI) regions having STIsidewalls defining a first width and a first height of the trench; anelectronic device fin comprising a height of the fin layer extendingabove etched top surfaces of the plurality of STI regions; and a firstconformal thickness of a first conformal epitaxial material on sidewallsand a top surface of the electronic device fin.

In Example 16, the subject matter of Example 15 can optionally includewherein the fin epitaxial material epitaxially has a single crystalstructure grown from the substrate surface, wherein the first conformalthickness has a single crystal structure grown from the sidewallsurfaces and top surface of the electronic device fin, and wherein thefirst conformal thickness crystal structure is a different atomicstructure than a polycrystaline atomic structure of the plurality of STIregions.

In Example 17, the subject matter of Example 15 can optionally includewherein the fin epitaxial material comprises a device channel material,and the first conformal epitaxial material comprises a gate buffermaterial formed over a portion of a total length of the channelmaterial.

In Example 18, the subject matter of Example 17 can optionally includewherein the fin epitaxial material comprises a buffer material, and thefirst conformal epitaxial material comprises a channel material formedover all of a total length of the channel material.

In Example 19, the subject matter of Example 15 can optionally includefurther comprising: a second conformal thickness of a second conformalepitaxial material on side alls and a top surface of the first conformalthickness.

In Example 20, the subject matter of Example 15 can optionally includewherein the fin layer is a first fin layer, the fin epitaxial materialis a first fin epitaxial material, the trench is a first trench, theplurality of STI regions are a first plurality of STI regions havingfirst STI sidewalls, the top surface of the fin layer is a first topsurface, and further comprising: a second On layer of a second finepitaxial material on the substrate surface at a bottom of a secondtrench formed between a second plurality shallow trench isolation (STI)regions having second STI sidewalls defining the first width and thefirst height of the second trench; a second electronic device fincomprising a second height of the second fin layer extending aboveetched top surfaces of the second plurality of STI regions; and a secondconformal thickness of a second conformal epitaxial material onsidewalls and a top surface of the second electronic device fin.

In Example 21, the subject matter of Example 20 can optionally includefurther comprising: a blanket buffer layer of a blanket buffer epitaxialmaterial on the substrate surface, a top surface of the blanket layerforming a bottom of the first and second trenches, wherein the first andsecond fin layers are grown in the first and second trenches from thetop surface of the blanket layer; a second buffer epitaxial material onthe top surface of the blanket buffer epitaxial material in the firsttrench; and a different, third buffer epitaxial material on the topsurface of the blanket buffer epitaxial material in the second trench.

Example 22 is a system for computing comprising: microprocessor coupledto a memory, the microprocessor having at least one electronic devicefin having: a fin layer of a fin epitaxial material on a substratesurface at a bottom of a trench formed between a plurality shallowtrench isolation (STI) regions having STI sidewalls defining a firstwidth and a first height of the trench; an electronic device fincomprising a height of the fin layer extending above etched top surfacesof the plurality of STI regions; and a first conformal thickness of afirst conformal epitaxial material on sidewalls and a top surface of theelectronic device fin.

In Example 23, the subject matter of Example 22 can optionally includewherein the fin epitaxial material epitaxially has a single crystalstructure grown from the substrate surface, wherein the first conformalthickness has a single crystal structure grown from the sidewallsurfaces and top surface of the electronic device fin, and wherein thefirst conformal thickness crystal structure is a different atomicstructure than a polycrystalline atomic structure of the plurality ofSTI regions.

In Example 24, the subject matter of Example 22 can optionally includefurther comprising: a second conformal thickness of a second conformalepitaxial material on sidewalls and a top surface of the first conformalthickness.

Example 25 is an apparatus comprising means for performing the method ofany one of claims 1-14.

In the description above, for the purposes of explanation, numerousspecific details have been set forth in order to provide a thoroughunderstanding of the embodiments. It will be apparent however, to oneskilled in the art, that one or more other embodiments may be practicedwithout some of these specific details. The particular embodimentsdescribed are not provided to limit embodiments of the invention but toillustrate it. The scope of the embodiments of the invention is not tobe determined by the specific examples provided above but only by theclaims below. In other instances, well-known structures, devices, andoperations have been shown in block diagram form or without detail inorder to avoid obscuring the understanding of the description. Whereconsidered appropriate, reference numerals or terminal portions ofreference numerals have been repeated among the figures to indicatecorresponding or analogous elements, which may optionally have similarcharacteristics.

It should also be appreciated that reference throughout thisspecification to “one embodiment”, “an embodiment”, “one or moreembodiments”, or “different embodiments”, for example, means that aparticular feature may be included in the practice of the embodiments.Similarly, it should be appreciated that in the description variousfeatures are sometimes grouped together in a single embodiment, figure,or description thereof for the purpose of streamlining the disclosureand aiding in the understanding of various inventive aspects ofembodiments. This method of disclosure, however, is not to beinterpreted as reflecting an embodiment that requires more features thanare expressly recited in each claim. Rather, as the following claimsreflect inventive aspects of embodiments that may lie in less than allfeatures of a single disclosed embodiment. For example, although thedescriptions and figures above describe forming fin 1145 adjacent to fin1146; and fin 1845 adjacent to fin 1846, the descriptions and figuresabove can be applied to forming any of those fins adjacent to any ofthose fins (e.g., including 1145 adjacent to fin 1145). Thus, the claimsfollowing the Detailed Description are hereby expressly incorporatedinto this Detailed Description, with each claim standing on its own as aseparate embodiment of the invention.

1. A method to form an electronic device fin comprising: epitaxiallygrowing a fin layer of a fin epitaxial material from a substrate surfaceat a bottom of a trench formed between a plurality of shallow trenchisolation (STI) regions having STI sidewalls defining a first width anda first height of the trench; patterning a top surface of the fin layerand etching the plurality of STI regions to form an electronic devicefin from a height of the fin layer extending above etched top surfacesof the plurality of STI regions; and epitaxially cladding a firstconformal thickness of a first conformal epitaxial material on sidewallsurfaces and a top surface of the electronic device fin.
 2. The methodof claim 1, wherein epitaxially cladding includes growing the firstconformal thickness of a single crystal conformal epitaxial materialfrom the sidewall surfaces and from the top surface of the electronicdevice fin.
 3. The method of claim 1, wherein epitaxially claddingincludes growing the first conformal thickness of a single crystalconformal epitaxial material across portions of top surfaces of theplurality of STI regions; but not growing the first conformal thicknessof the first conformal epitaxial material from a polycrystallinematerial of the portions of top surfaces of the plurality of STIregions.
 4. The method of claim 1, wherein the fin epitaxial materialcomprises a device channel material, and the first conformal epitaxialmaterial comprises a gate buffer material formed over a portion of atotal length of the channel material.
 5. The method of claim 4, whereinthe first buffer epitaxial material comprises an ART epitaxial InP orSiGe material; the second buffer epitaxial material comprises an ARTepitaxial buffer InAlAs or SiGe material; the device channel materialcomprises an InGaAs or Ge material; and the first conformal epitaxialmaterial comprises an InP or Si material formed over a portion of atotal length of the channel material.
 6. The method of claim 1, whereinthe fin material comprises a buffer material, and the first conformalepitaxial material comprises a channel material formed over all of atotal length of the channel material.
 7. The method of claim 6, whereinthe first buffer material comprises an epitaxial InP or SiGe material;and the second buffer material comprises an epitaxial buffer InAlAs orSiGe material; and the first conformal epitaxial material comprises anInGaAs or Ge channel material formed over a total length of the channelmaterial.
 8. The method of claim 1, further comprising: epitaxiallycladding a second conformal thickness of a second conformal epitaxialmaterial on sidewalls and a top surface of the first conformalthickness.
 9. The method of claim 8, wherein the fin material comprisesone of a buffer material and a device channel material; the firstconformal epitaxial material comprises one of a channel material and agate buffer material; and the second conformal epitaxial materialcomprises one of a device gate dielectric and a junction region materialformed over the first conformal epitaxial material.
 10. The method ofclaim 8, further comprising: epitaxially cladding a third conformalthickness of a third conformal epitaxial material on sidewalls and a topsurface of the first conformal thickness.
 11. The method of claim 10,wherein the fin material comprises one of a buffer material and a devicechannel material; the first conformal epitaxial material comprises oneof a channel material and a gate buffer material; second conformalepitaxial material comprises a device gate dielectric; and the thirdconformal epitaxial material comprises a junction region material formedover the first conformal epitaxial material.
 12. The method of claim 1,wherein the fin layer is a first fin layer, the fin epitaxial materialis a first fin epitaxial material, the trench is a first trench, theplurality of STI regions are a first plurality of STI regions havingfirst STI sidewalls, the top surface of the fin layer is a first topsurface, and further comprising: epitaxially growing a second fin layerof a second fin epitaxial material from the substrate surface at abottom of a second trench formed between a second plurality of STIregions having second STI sidewalls defining the first width and thefirst height of the second trench; patterning a second buffer topsurface of the second fin layer and etching the second plurality of STIregions to form a second electronic device fin from a height of thesecond fin layer extending above etched top surfaces of the secondplurality of STI regions; epitaxially cladding a second conformalthickness of a second conformal epitaxial material on sidewalls and atop surface of the second electronic device fin.
 13. The method of claim12, wherein the first fin layer comprises a first buffer layer of afirst buffer epitaxial material, and a second buffer layer of a secondbuffer epitaxial material grown from the first buffer epitaxial materialin the first trench; wherein the second fin layer comprises the firstbuffer layer of the first buffer epitaxial material, the second bufferlayer of the second buffer epitaxial material grown from the firstbuffer epitaxial material, and a third buffer layer of a third bufferepitaxial material grown from the second buffer epitaxial material inthe second trench; wherein the first conformal epitaxial materialcomprises a first channel material formed over all of a total length ofthe second buffer layer over the first trench; and wherein the fourthconformal epitaxial material comprises a different, second channelmaterial formed over all of a total length of the third buffer layerover the second trench.
 14. The method of claim 12, further comprising:prior to growing the fin layer, epitaxially growing a blanket bufferlayer of a blanket buffer epitaxial material from the substrate surface,a top surface of the blanket layer forming a bottom of the first andsecond trenches, wherein the first and second fin layers are grown inthe first and second trenches from the top surface of the blanket layer;epitaxially growing a second buffer epitaxial material from the topsurface of the blanket buffer epitaxial material in the first trench;and epitaxially growing a different, third buffer epitaxial materialfrom the top surface of the blanket buffer epitaxial material in thesecond trench.
 15. An electronic device fin comprising: a fin layer of afin epitaxial material on a substrate surface at a bottom of a trenchformed between a plurality shallow trench isolation (STI) regions havingSTI sidewalls defining a first width and a first height of the trench;an electronic device fin comprising a height of the fin layer extendingabove etched top surfaces of the plurality of STI regions; and a firstconformal thickness of a first conformal epitaxial material on sidewallsand a top surface of the electronic device fin.
 16. The device of claim15, wherein the fin epitaxial material epitaxially has a single crystalstructure grown from the substrate surface, wherein the first conformalthickness has a single crystal structure grown from the sidewallsurfaces and top surface of the electronic device fin, and wherein thefirst conformal thickness crystal structure is a different atomicstructure than a polycrystalline atomic structure of the plurality ofSTI regions.
 17. The device of claim 15, wherein the fin epitaxialmaterial comprises a device channel material, and the first conformalepitaxial material comprises a gate buffer material formed over aportion of a total length of the channel material.
 18. The device ofclaim 17, wherein the fin epitaxial material comprises a buffermaterial, and the first conformal epitaxial material comprises a channelmaterial formed over all of a total length of the channel material. 19.The device of claim 15, further comprising: a second conformal thicknessof a second conformal epitaxial material on sidewalls and a top surfaceof the first conformal thickness.
 20. The device of claim 15, whereinthe fin layer is a first fin layer, the fin epitaxial material is afirst fin epitaxial material, the trench is a first trench, theplurality of STI regions are a first plurality of STI regions havingfirst STI sidewalls, the top surface of the fin layer is a first topsurface, and further comprising: a second fin layer of a second finepitaxial material on the substrate surface at a bottom of a secondtrench formed between a second plurality shallow trench isolation (STI)regions having second STI sidewalls defining the first width and thefirst height of the second trench; a second electronic device fincomprising a second height of the second fin layer extending aboveetched top surfaces of the second plurality of STI regions; and a secondconformal thickness of a second conformal epitaxial material onsidewalls and a top surface of the second electronic device fin.
 21. Thedevice of claim 20, further comprising: a blanket buffer layer of ablanket buffer epitaxial material on the substrate surface, a topsurface of the blanket layer forming a bottom of the first and secondtrenches, wherein the first and second fin layers are grown in the firstand second trenches from the top surface of the blanket layer; a secondbuffer epitaxial material on the top surface of the blanket bufferepitaxial material in the first trench; and a different, third bufferepitaxial material on the top surface of the blanket buffer epitaxialmaterial in the second trench.
 22. A system for computing comprising:microprocessor coupled to a memory, the microprocessor having at leastone electronic device fin having: a fin layer of a fin epitaxialmaterial on a substrate surface at a bottom of a trench formed between aplurality shallow trench isolation (STI) regions having STI sidewallsdefining a first width and a first height of the trench; an electronicdevice fin comprising a height of the fin layer extending above etchedtop surfaces of the plurality of STI regions; and a first conformalthickness of a first conformal epitaxial material on sidewalls and a topsurface of the electronic device fin.
 23. The system of claim 22,wherein the fin epitaxial material epitaxially has a single crystalstructure grown from the substrate surface, wherein the first conformalthickness has a single crystal structure grown from the sidewallsurfaces and top surface of the electronic device fin, and wherein thefirst conformal thickness crystal structure is a different atomicstructure than a polycrystalline atomic structure of the plurality ofSTI regions.
 24. The system of claim 22, further comprising: a secondconformal thickness of a second conformal epitaxial material onsidewalls and a top surface of the first conformal thickness.
 25. Anapparatus formed by the method of claim 1.